October 15, 2025October 15, 2025 vibssingh

How to create and write JSON with JSON.simple in Java

Last Updated On

October 15, 2025

This article shows how to write a JSON using JSON.simple.

This project was formerly JSON.simple 1.x from a Google code project by Yidong, now maintained by Clifton Labs, read this JSON.simple history.

The JSON-simple is a light weight library which is used to process JSON objects. Using this you can read or, write the contents of a JSON document using a Java program.

JSON.simple is available at the Central Maven Repository. Maven users add this to the POM.

<!-- https://mvnrepository.com/artifact/com.github.cliftonlabs/json-simple -->
<dependency>
    <groupId>com.github.cliftonlabs</groupId>
    <artifactId>json-simple</artifactId>
    <version>4.0.1</version>
</dependency>

If the project is Gradle, add the below dependency in build.gradle.

// https://mvnrepository.com/artifact/com.github.cliftonlabs/json-simple
implementation("com.github.cliftonlabs:json-simple:4.0.1")

Write Simple JSON to File using JSON.simple

Below is the sample simple JSON that will be generated. The file will be saved in resources/Payloads as Employee.json.

{ 
    "Working Days":[ 
                             "Monday",
                             "Tuesday",
                             "Wednesday"
                             ],
    "Salary":4500.0,
    "Name":"Vibha"
}

The entire program looks like as shown below:

import com.github.cliftonlabs.json_simple.JsonArray;
import com.github.cliftonlabs.json_simple.JsonObject;
import com.github.cliftonlabs.json_simple.Jsoner;

import java.io.FileWriter;
import java.io.IOException;

public class WriteSimpleJson {
    public static void main(String[] args) {

        // JSON String
        JsonObject jsonObject = new JsonObject();
        jsonObject.put("Name", "Vibha");
        jsonObject.put("Salary", 4500.00);

        // JSON Array
        JsonArray list = new JsonArray();
        list.add("Monday");
        list.add("Tuesday");
        list.add("Wednesday");

        jsonObject.put("Working Days", list);
        System.out.println(Jsoner.serialize(jsonObject));

        try (FileWriter fileWriter = new FileWriter("src/test/resources/Payloads/Employee.json")) {
            Jsoner.serialize(jsonObject, fileWriter);

        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

The output of the above program is

Explanation

1. Creating a JSON Object

A `JsonObject` named `jsonObject` is created to hold data. Using `put()`, the code adds a “Name” field with the value “Vibha” and a “Salary” field with the value `4500.00` to the JSON object.

JsonObject jsonObject = new JsonObject();
jsonObject.put("Name", "Vibha");
jsonObject.put("Salary", 4500.00);

2. Creating a JSON Array

A `JsonArray` named `list` is created to contain multiple values. The days “Monday”, “Tuesday”, and “Wednesday” are added to the `list`. The JSON array list is added to the jsonObject under the key “Working Days”.

JsonArray list = new JsonArray();
list.add("Monday");
list.add("Tuesday");
list.add("Wednesday");
jsonObject.put("Working Days", list);

3. Writing JSON to a File

A FileWriter is used to open the file src/test/resources/Payloads/Employee.json for writing. The Jsoner.serialize() method serializes the jsonObject and writes it to the file, capturing the constructed JSON structure.

 try (FileWriter fileWriter = new FileWriter("src/test/resources/Payloads/Employee.json")) {
            Jsoner.serialize(jsonObject, fileWriter);

  }

Write Complex JSON to File using JSON.simple

Below is the complex JSON which will be generated.

{
  "Working Days": ["Monday","Tuesday","Wednesday"],
  "Salary":{
    "Bonus":{
      "Quaterly":125.0,
      "Monthly":45.0,
      "Yearly":500.0
    },
    "Fixed":4000.0
  },"Name": {
  "Forename":"Vibha",
  "Surname":"Singh"
 }
}

The entire program looks like as shown below:

import com.github.cliftonlabs.json_simple.JsonArray;
import com.github.cliftonlabs.json_simple.JsonObject;
import com.github.cliftonlabs.json_simple.Jsoner;

import java.io.FileWriter;
import java.io.IOException;

public class WriteComplexJson {

    public static void main(String[] args) {

        JsonObject jsonObject = new JsonObject();

        //Name
        JsonObject name = new JsonObject();
        name.put("Forename", "Vibha");
        name.put("Surname", "Singh");
        jsonObject.put("Name", name);

        //Salary
        JsonObject salary = new JsonObject();
        salary.put("Fixed", 4000.00);

        //Bonus
        JsonObject bonus = new JsonObject();
        bonus.put("Monthly", 45.00);
        bonus.put("Quaterly", 125.00);
        bonus.put("Yearly", 500.00);

        salary.put("Bonus",  bonus);
        jsonObject.put("Salary", salary);

        // JSON Array
        JsonArray list = new JsonArray();
        list.add("Monday");
        list.add("Tuesday");
        list.add("Wednesday");
        jsonObject.put("Working Days", list);

        System.out.println(Jsoner.serialize(jsonObject));

        try (FileWriter fileWriter = new FileWriter("src/test/resources/Payloads/EmployeeDetails.json")) {
            Jsoner.serialize(jsonObject, fileWriter);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

The output of the above program is

I have saved this file in resources/Payloads as EmployeeDetails.json.

Explanation

1.Creating JSON Objects

Serves as the root JSON object to encapsulate all the other JSON objects and arrays

 JsonObject jsonObject = new JsonObject();

2. Name Object

A JsonObject named name is created. It contains two properties: “Forename” with the value “Vibha” and “Surname” with the value “Singh”. This name object is then added to the root jsonObject under the key “Name”.

JsonObject name = new JsonObject();
name.put("Forename", "Vibha");
name.put("Surname", "Singh");
jsonObject.put("Name", name);

3. Salary Object

A `JsonObject` named `salary` is created with a property “Fixed” representing a fixed salary amount of 4000.00.

//Salary
JsonObject salary = new JsonObject();
salary.put("Fixed", 4000.00);

4. Bonus Object

A `JsonObject` named `bonus` is created. It contains properties for different types of bonuses: “Monthly” (45.00), “Quarterly” (125.00), and “Yearly” (500.00).

The `bonus` object is then added as a property of the `salary` object under the key “Bonus”.

The complete `salary` object, now including the bonus details, is added to the root `jsonObject` under the key “Salary”.

//Bonus
JsonObject bonus = new JsonObject();
bonus.put("Monthly", 45.00);
bonus.put("Quaterly", 125.00);
bonus.put("Yearly", 500.00);

salary.put("Bonus",  bonus);
jsonObject.put("Salary", salary);

5. Creating a JSON Array

A `JsonArray` named `list` is created to represent the working days. The days “Monday”, “Tuesday”, and “Wednesday” are added to this array. This `list` is added to the root `jsonObject` under the key “Working Days”.

// JSON Array
JsonArray list = new JsonArray();
list.add("Monday");
list.add("Tuesday");
list.add("Wednesday");

jsonObject.put("Working Days", list);

6. Serialization of JSON

The entire `jsonObject` is serialized using `Jsoner.serialize()` and printed to the console, which converts the Java JSON structure into a JSON string.

jsonObject.put("Working Days", list);
System.out.println(Jsoner.serialize(jsonObject));

7. Writing the JSON to a File

The `try-with-resources` statement is used to ensure the `FileWriter` is closed automatically. A `FileWriter` writes the serialized JSON object to a file at `src/test/resources/Payloads/EmployeeDetails.json`.

 try (FileWriter fileWriter = new FileWriter("src/test/resources/Payloads/Employee.json")) {
            Jsoner.serialize(jsonObject, fileWriter); }

We are done! Congratulations on making it through this tutorial and hope you found it useful! Happy Learning!!

October 13, 2025October 13, 2025 vibssingh

Java – Multiple Choice Questions and Answers – Arrays

Last Updated On

October 13, 2025

HOME

Welcome to the Java Quiz! This blog post features 25 multiple-choice questions that explore the concepts of Arrays in Java.

1. What is an array in Java?

a) A data structure that can hold elements of different types
b) A class that allows storing single data type elements in a contiguous memory location
c) A collection of elements in no specific order
d) A method for sorting elements

Answer 1

b) A class that allows storing single data type elements in a contiguous memory location

Arrays in Java are used to store multiple values of the same data type in a contiguous memory location.

2. How do you instantiate an array of integers with 10 elements in Java?

a) int[] arr = new int[10];
b) int arr = new int(10);
c) int arr[10] = new int[];
d) int(10) arr = new int[];

Answer 2

a) int[] arr = new int[10];

3. What is the default value of an element in an int array in Java?

Choose one option

a) 1
b) 0
c) null
d) Undefined

Answer 3

b) 0

In Java, arrays of primitive types like int are initialized to their default values. The default value for int is 0

4. What will be the output of the following Java program?

class array_output 
    {
        public static void main(String args[]) 
        {
            int array_variable [] = new int[10];
	        for (int i = 0; i < 10; ++i) 
            {
                array_variable[i] = i;
                System.out.print(array_variable[i] + " ");
                i++;
            }
        } 
   }

Choose one option

a) 0 2 4 6 8
b) 1 3 5 7 9
c) 0 1 2 3 4 5 6 7 8 9
d) 1 2 3 4 5 6 7 8 9 10

Answer 4

a) 0 2 4 6 8

When an array is declared using new operator then all of its elements are initialized to 0 automatically. for loop body is executed 5 times as whenever controls comes in the loop i value is incremented twice, first by i++ in body of loop then by ++i in increment condition of for loop.

5. What is the maximum number of dimensions an array can have in Java?

a) 1
b) 255
c) 2
d) No theoretical limit

Answer 5

b) 255

Java allows arrays to have up to 255 dimensions.

6. What will be the output of the following Java program?

public class array_output {

    public static void main(String args[])
    {
        char array_variable [] = new char[10];
        for (int i = 0; i < 10; ++i)
        {
            array_variable[i] = 'i';
            System.out.print(array_variable[i] + "");
        }
    }
}

Choose one option

a) 1 2 3 4 5 6 7 8 9 10
b) 0 1 2 3 4 5 6 7 8 9 10
c) i j k l m n o p q r
d) i i i i i i i i i i

Answer 6

d) i i i i i i i i i i

When an array is declared using the new operator, all of its elements are automatically initialized to default values—0 for numeric types, null for reference types, and ‘\0’ (null character) for char.

7. What will be the output of the following Java program?

public class array_output {
    public static void main(String args[])
    {
        double num[] = {5.5, 10.1, 11, 12.8, 56.9, 2.5};
        double result;
        result = 0;
        for (int i = 0; i < 6; ++i)
            result = result + num[i];
            System.out.print(result/6);

    }
}

Choose one option

a) 16.34
b) 16.566666644
c) 16.46666666666667
d) 16.46666666666666

Answer 7

c) 16.46666666666667

8. What happens if you try to access an index of an array that is out of bounds?

Choose one option

a) Compile-time error
b) Returns null
c) Throws ArrayIndexOutOfBoundsException
d) None of the above

Answer 8

c) Throws ArrayIndexOutOfBoundsException

9. How do you declare an array of strings?

a) String[] arr;
b) String arr[];
c) String arr();
d) String arr{};

Answer 9

a) String[] arr;

This is the standard way of declaring an array of strings in Java.

10. Which of the following is a valid declaration and initialization of String array in Java

a) String[] names ={“Tim”,”Mark”,”Charlie”}
b) String names[] ={“Tim”,”Mark”,”Charlie”}
c) String[3] names ={“Tim”,”Mark”,”Charlie”}
d) Both a) and b)
e) Both a) and c)

Answer 10

d) Both a) and b)

String[3] names = {“Tim”, “Mark”, “Charlie”};` is incorrect because Java does not allow specifying the size of the array within square brackets during initialization in this manner.

11. What will be the output?

public class Test {
    public static void main(String[] args) {
        String[] arr = {"Java", "Python", "C++"};
       System.out.println(arr[1]);
    }
}

Choose one option

a) Java
b) Python
c) C++
d) Compilation error

Answer 11

b) Python

arr[1] accesses the second element of the array, which is “Python”.

12. Which of the following statements is true?

Choose one option

a) Arrays are immutable
b) Arrays are objects
c) Arrays store elements of any data type
d) Arrays automatically grow

Answer 12

b) Arrays are objects

In Java, arrays are objects and are part of the java.lang package.

13. What is the primary use of the `System.arraycopy()` method in Java?

Choose one option

a) To copy one array to another
b) To reverse an array
c) To sort an array
d) To find an element in an array

Answer 13

a) To copy one array to another

System.arraycopy() is used to copy elements from one array to another.

14. What is printed by the following code snippet?

public class Test {
    public static void main(String[] args) {
       int[] arr = new int[5];
      System.out.println(arr[1]);
    }
}

Choose one option

a) 0
b) null
c) undefined
d) Compilation error

Answer 14

a) 0

Integer arrays are initialized to 0 by default.

15. What will be the result of this program?

public class array_output {
    public static void main(String args[])
    {
        int[] arr = {1, 2, 3, 4};
        System.out.println(arr.length);
    }
}

Choose one option

a) 0
b) 3
c) 4
d) Compilation error

Answer 15

c) 4

arr.length returns the number of elements in the array, which is 4.

16. What exception is thrown by Java code when trying to store values in a sufficiently large dimension of an array but with the wrong data type?

Choose one option

a) ArrayIndexOutOfBoundsException
b) IllegalArgumentException
c) ClassCastException
d) ArrayStoreException

Answer 16

d) ArrayStoreException

ArrayStoreException occurs when attempting to store incorrect types into arrays of object types.

17. Which of the following is not a valid way to declare a two-dimensional array in Java?

Choose one option

a) int[][] arr = new int[3][3];
b) int arr[][] = new int[3][3];
c) int[] arr = new int[3][];
d) int[][] arr = new int[][];

Answer 17

d) int[][] arr = new int[][];

Option D is invalid because while it declares a two-dimensional array, it does not specify the size of either dimension at the time of declaration.

18. What is the correct way to iterate over a Java array using an enhanced for loop?

a) for (int i : arr)
b) for (int i = 0; i < arr.length; i++)
c) for (arr : int i)
d) for (arr i : int)

Answer 18

a) for (int i : arr)

The enhanced for loop in Java is written as for (type variable : array).

19. What will happen if you try to store a double value into an int array?

a) The value will be rounded
b) The value will be truncated
c) A ClassCastException will be thrown
d) A compile-time error

Answer 19

d) A compile-time error

You cannot store a double value in an int array without explicit casting, leading to a compile-time error.

20. What is the output of the following code?

public class array_output {
    public static void main(String args[])
    {
        int[] arr = {2, 4, 6, 8};
        System.out.println(arr[arr.length]);
    }
}

Choose one option

a) 8
b) 4
c) 0
d) ArrayIndexOutOfBoundsException

Answer 20

d) ArrayIndexOutOfBoundsException

Since array indices are 0-based, accessing arr[arr.length] is out of bounds. The valid indices for this array are from 0 to arr.length – 1.

21. What is the output of the following code?

public class array_output {
    public static void main(String args[]) {
        int[] arr = {1, 2, 3, 4, 5};
        for (int i = 0; i < arr.length; i++) {
            arr[i] = arr[i] * 2;
        }
        System.out.println(arr[2]);
    }
}

Choose one option

a) 3
b) 6
c) 8
d) 10

Answer 21

b) 6

The loop multiplies each element by 2. Therefore, arr[2] becomes 3 * 2 = 6.

22. What will be the output of the below program?

public class array_output {
    
    public static void main(String args[]) {
        int[] arr = {10, 20, 30, 40};
        System.out.println(arr[1] + arr[2]);
    }
}

Choose one option

a) 30
b) 50
c) 60
d) 70

Answer 22

b) 50

arr[1] is 20 and arr[2] is 30, so the sum is 20 + 30 = 50.

23. Can you resize an array in Java after it is created?

Choose one option

a) Yes
b) No

Answer 23

b) No

24. How can you access the element at the second row and third column of a two-dimensional array “matrix”?

a) matrix[3][2]
b) matrix[2, 3]
c) matrix[1][2]
d) matrix[2:3]

Answer 24

c) matrix[1][2]

Array indexing starts at 0 in Java, so the second row is index 1, and the third column is index 2.

25. What will be the default value of the elements in a two-dimensional array of type `int[][]` in Java?

a) null
b) 0
c) undefined
d) Compilation error

Answer 25

b) 0

For arrays of primitive data types like int, the default value of the elements is 0.

We would love to hear from you! Please leave your comments and share your scores in the section below

October 9, 2025October 9, 2025 vibssingh

How to Read JSON with JSON.simple

Last Updated On

October 9, 2025

HOME

This article shows how to read JSON using JSON.simple.

This project was formerly JSON.simple 1.x from a Google code project by Yidong, now maintained by Clifton Labs, read this JSON.simple history

JSON.simple is available at the Central Maven Repository. Maven users add this to the POM.

<!-- https://mvnrepository.com/artifact/com.github.cliftonlabs/json-simple -->
<dependency>
    <groupId>com.github.cliftonlabs</groupId>
    <artifactId>json-simple</artifactId>
    <version>4.0.1</version>
</dependency>

If the project is Gradle, add the below dependency in build.gradle.

// https://mvnrepository.com/artifact/com.github.cliftonlabs/json-simple
implementation("com.github.cliftonlabs:json-simple:4.0.1")

Read Simple JSON from File using JSON.simple

Below is the sample JSON which is used as an example . I have saved this file in resources/Payloads as simple.json.

{
  "store": {
    "book": "Harry Potter",
    "author": "J K Rowling",
    "price": 100
  }
}

The complete program looks like as shown below:

import com.github.cliftonlabs.json_simple.JsonException;
import com.github.cliftonlabs.json_simple.JsonObject;
import com.github.cliftonlabs.json_simple.Jsoner;

import java.io.IOException;
import java.math.BigDecimal;
import java.nio.file.Files;
import java.nio.file.Paths;

public class SimpleJsonExample {

    public static void main(String args[]) throws IOException {

        String jsonString = new String(Files.readAllBytes(Paths.get("src/test/resources/Payloads/simple.json")));
        try {
            JsonObject jsonObject = (JsonObject) Jsoner.deserialize(jsonString);

            // Accessing the "store" object
            JsonObject store = (JsonObject) jsonObject.get("store");

            // Accessing the "book" object
            String book = (String) store.get("book");
            System.out.println("Book: " + book);

            // Accessing the "author" object
            String author = (String) store.get("author");
            System.out.println("Author - " + author);

            // Accessing the "price" field
            BigDecimal price = (BigDecimal) store.get("price");
            System.out.println("Price: " + price);

        } catch (JsonException e) {
            throw new RuntimeException(e);
        }
    }
}

The output of the above program is

Explanation

1.Read all bytes from the file path and converting it to a String.

String jsonString = new String(Files.readAllBytes(Paths.get("src/test/resources/Payloads/simple.json")));

2. Parse the jsonString into a JsonObject using Jsoner.deserialize(jsonString). The parsed JSON object is stored in the jsonObject variable.

JsonObject jsonObject = (JsonObject) Jsoner.deserialize(jsonString);

3. The code accesses the nested “store” object using jsonObject.get(“store”) and casts it to a JsonObject. It then retrieves specific fields from this “store” object.

 JsonObject store = (JsonObject) jsonObject.get("store");

4. Extracts the “book” field and casts it to a String, then prints it.

String book = (String) store.get("book");
System.out.println("Book: " + book);

5. Extracts the “author” field and casts it to a String, then prints it.

String author = (String) store.get("author");
System.out.println("Author - " + author);

6. Extracts the “price” field and casts it to a BigDecimal, then prints it.

BigDecimal price = (BigDecimal) store.get("price");
System.out.println("Price: " + price);

Read Complex JSON from File using JSON.simple

Below is the complex JSON. I have saved this file in resources/Payloads as complex.json.

public class ComplexJsonExample {

    public static void main(String args[]) throws IOException {

        String jsonString = new String(Files.readAllBytes(Paths.get("src/test/resources/Payloads/complex.json")));
        try {
            JsonObject jsonObject = (JsonObject) Jsoner.deserialize(jsonString);

            // Accessing the "store" object
            JsonObject store = (JsonObject) jsonObject.get("store");

            // Accessing the "book" array
            JsonArray books = (JsonArray) store.get("book");
            for (Object bookObj : books) {
                JsonObject book = (JsonObject) bookObj;
                String category = (String) book.get("category");
                String author = (String) book.get("author");
                String title = (String) book.get("title");
                BigDecimal price = (BigDecimal) book.get("price");

                System.out.println("Book: " + title + " (Category: " + category + ", Author: " + author + ", Price: " + price + ")");
            }

            // Accessing the "bicycle" object
            JsonObject bicycle = (JsonObject) store.get("bicycle");
            String color = (String) bicycle.get("color");
            BigDecimal bicyclePrice = (BigDecimal) bicycle.get("price");
            System.out.println("Bicycle: Color - " + color + ", Price - " + bicyclePrice);

            // Accessing the "expensive" field
            BigDecimal expensiveValue = (BigDecimal) jsonObject.get("expensive");
            System.out.println("Expensive threshold: " + expensiveValue);

        } catch (JsonException e) {
            throw new RuntimeException(e);
        }
    }
}

The output of the above program is

Explanation

1.Read all bytes from the file path and converting it to a String.

String jsonString = new String(Files.readAllBytes(Paths.get("src/test/resources/Payloads/complex.json")));

2. Parse the jsonString into a JsonObject using Jsoner.deserialize(jsonString). The parsed JSON object is stored in the jsonObject variable.

JsonObject jsonObject = (JsonObject) Jsoner.deserialize(jsonString);

3. The code assumes that within the “store” object, there is a key “book” which corresponds to a JSON array. It retrieves this array and stores it in a JsonArray variable named books.

 // Accessing the "store" object
JsonObject store = (JsonObject) jsonObject.get("store");

// Accessing the "book" array
JsonArray books = (JsonArray) store.get("book");

4. A for-each loop iterates over each element in the books array. Each element is considered an object, and it’s cast to JsonObject named book. Within each iteration, several attributes of the book JSON object are accessed like category, author, title, price

 for (Object bookObj : books) {
       JsonObject book = (JsonObject) bookObj;
       String category = (String) book.get("category");
       String author = (String) book.get("author");
       String title = (String) book.get("title");
       BigDecimal price = (BigDecimal) book.get("price");

        System.out.println("Book: " + title + " (Category: " + category + ", Author: " + author + ", Price: " + price + ")");
      }

5. The code accesses the nested “bicycle” object using jsonObject.get(“bicycle”) and casts it to a JsonObject. It then retrieves specific fields from this “bicycle” object. Extracts the “color” and “price” field and casts it to a String and BigDecimal, then prints it.

 // Accessing the "bicycle" object
 JsonObject bicycle = (JsonObject) store.get("bicycle");
String color = (String) bicycle.get("color");
BigDecimal bicyclePrice = (BigDecimal) bicycle.get("price");
System.out.println("Bicycle: Color - " + color + ", Price - " + bicyclePrice);

6. Extracts the “expensive” field and casts it to a BigDecimal, then prints it.

BigDecimal expensiveValue = (BigDecimal) jsonObject.get("expensive");
System.out.println("Expensive threshold: " + expensiveValue);

We are done! Congratulations on making it through this tutorial and hope you found it useful! Happy Learning!!

October 7, 2025October 31, 2025 vibssingh

A Complete Guide to ETL Testing

Last Updated On

October 31, 2025

HOME

ETL testing is a critical phase. It ensures the integrity and reliability of data within data warehouses. It also plays a vital role in business intelligence systems. This article explores essential methodologies and best practices in ETL testing. It highlights ETL testing’s role in driving high-quality data management and reliable analytical outcomes in organizations.

Table of Contents

What is ETL (Extract, Transform, Load)

Extract/transform/load (ETL) is a data integration approach. It pulls information from various sources. It transforms the information into defined formats and styles. Finally, it loads the data into a database, a data warehouse, or some other destination.

What is ETL testing and why do we need it?

ETL Testing stands for Extract, Transform, and Load Testing, which is a process used to ensure that the data is correctly extracted from a source system, transformed according to business rules, and loaded accurately into a target system, typically a data warehouse. This testing is crucial for ensuring data integrity, accuracy, and reliability.

It is important to use ETL testing in the following situations:

1. Initial Data Load into a New Data Warehouse: Validate that the entire dataset is accurately transferred, transformed, and loaded into the data warehouse during the initial setup.

2. Adding a New Data Source to an Existing Data Warehouse: Assess compatibility between new data sources and existing systems, ensuring proper integration without quality loss.

3. Data Migration: Validate that all data from old systems is completely and accurately migrated to the new system.

4. High Data Quality for Analytics or Decision-Making: Quality assurance is crucial before using data for analytics and business intelligence. Conduct thorough audits for data quality, check for consistency, accuracy, validity, and correctness across different data sources, and ensure transformations align with business requirements.

Stages of ETL Testing LifeCycle

1. Identifying data sources and gathering business requirements: The first step is to understand expectations and the scope of the project. This process includes gathering and analyzing ETL process requirements, including source data, transformation logic, and target data specifications. It’s important to clearly define and document the data model as it will act as a reference for the Quality Assurance (QA) team.

2. Test Planning: This step involves developing a comprehensive test plan outlining the scope of testing, objectives, resources, timelines, and risk factors. Here, we choose the appropriate testing tools and frameworks that will be used for automation or manual testing.

3. Test Design: The next step is designing ETL mapping for various scenarios. The design contains creating detailed test cases and test scenarios based on the requirements defined in the previous steps. The testing team is also required to write SQL scripts and define the transformational rules.

4. Test Environment Setup: This step involves preparing the test environment, which includes setting up the required source and target systems, configuring the ETL tools, and ensuring data accessibility. Make sure that necessary permissions and network configurations are in place.

5. Validating extracted data: The first step of ETL is extraction, and at this stage, the testers ensure that all the data have been extracted cleanly and completely. It’s essential to detect defects and fix bugs at the initial stage to lessen the chances of a misleading analysis.

6. Validating data transformation: The transformed data matches the schema of the target repository. The QA team makes sure that the data type syncs with the mapping document.

7. Verifying loaded data: The data is taken from the primary source system and converted into the desired format. After conversion, it is loaded to the target warehouse. Here, the testers reconcile the data and check for data integrity.

8. Preparing summary report: After the test, the QA team prepares a summary report. It contains all the findings of the tests and documents bugs and errors that were detected during the testing process.

9. Test Closure: Filing and submitting ETL test closure report.

Different types of testing involved in an ETL process

1.Source to target count testing – In this testing, we verifies that the number of records loaded into the target database matches the expected record count.

2. Source to target data testing – It ensures projected data is added to the target system without loss or truncation, and that the data values meet expectations after transformation.

3. Metadata testing – It performs data type, length, index, and constraint checks of ETL application metadata (load statistics, reconciliation totals, and data quality metrics).

4. Data Transformation Testing – It ensures that all transformations applied to the source data are accurate and correctly implemented according to the business requirements.

5. Data quality testing – It runs syntax tests (invalid characters, pattern, case order) and reference tests (number, date, precision, null check) to make sure the ETL application accepts default values and rejects and reports invalid data.

6. Data integration testing – It confirms that the data from all sources has loaded to the target data warehouse correctly and checks threshold values.

7. Performance Testing – Assesses the performance of the ETL process, ensuring that it completes within acceptable time limits and that the system can handle expected data volumes and loads.

8. Data Integration Testing – Validates that data from different sources is integrated as expected and that relationships among data entities are maintained correctly in the target system.

9. Scalability Testing – Evaluates the ETL system’s ability to scale up and handle increased data volumes and loads without performance degradation.

10. End-to-End Testing – Validates the entire ETL process from data extraction to loading and ensures the integration of data across the full data pipeline.

11. Report testing – It reviews data in summary report, verifying layout and functionality are as expected, and makes calculations.

Various ETL Testing Tools

1. Informatica Data Validation: Informatica is a widely used tool. It provides automated testing capabilities for data validation and transformation. This ensures data integrity within the ETL process.

2. QuerySurge: QuerySurge leverage AI to automate and scale data validation process. QuerySurge uses AI-powered test creation. It employs a scalable architecture and offers seamless CI/CD integration. These features ensure data integrity at every stage of the pipeline. They accelerate delivery, reduce risk, and drive confident decision-making.

3. Talend Open Studio for Data Integration: Talend is a powerful ETL tool. It also supports testing functionalities. Users can build and automate data pipelines. They can verify data transformations and integrations.

4. Tricentis Tosca: Tricentis is known for its model-based testing approach. Tosca enables organizations to automate end-to-end testing processes, including ETL testing, and ensure comprehensive data quality checks.

5. ETL Validator: This tool is specifically designed for ETL testing. It automates ETL/ELT testing to ensure data integrity. It reduces migration time. It also improves quality with low-code, AI-driven validation across cloud and on-prem pipelines.

6. Datagaps ETL Validator: Datagaps ETL Validator is enterprise-grade tool offers extensive testing capabilities. It includes comparison of source and target data. It also validates transformation logic, which further ensures data accuracy after ETL processes.

7. IBM InfoSphere DataStage: DataStage is primarily an ETL tool. It provides integrated testing functionalities. These ensure data accuracy and consistency during ETL operations.

ETL testing challenges

Potential complexity of data transformations – Transformations of large datasets can be time-consuming and complex.
Data Quality Issues – Data is often messy and full of errors; ETL testing needs clean, accurate data to have healthy results.
Lack of Standardization – Different formats and standards across various source systems complicate the testing process, requiring extensive validation efforts.
Resource intensiveness – ETL testing can be resource intensive when dealing with large, complex source systems.
Data source changes – Changes to data sources impact the completeness and accuracy of data quality.
Complex processes – Complex data integrations and business processes can cause problems.
Slow performance – Slow processing or slow end-to-end performance caused by massive data volumes can impact data accuracy and completeness.
Resource Constraints – Difficulty finding people with skilled testing personnel and technical infrastructure and data health expertise.

October 3, 2025October 3, 2025 vibssingh

ETL Testing – Multiple Choice Questions and Answers – MCQ2

Last Updated On

October 3, 2025

HOME

Welcome to the ETL Testing Quiz! This blog post features 25 multiple-choice questions that explore the concepts of ETL Testing.

1. Using an ____ tool, data is extracted from multiple data sources, transformed, and loaded into a data warehouse after joining fields, calculating, and removing incorrect data fields.

a) ETL
b) TEL
c) LET
d) LTE

Answer 1

a) ETL

2. Which phase of ETL testing involves comparing source data with target data?

a) Production Validation Testing
b) Source to Target Count Testing
c) Source to Target Data Testing
d) Metadata Testing

Answer 2

c) Source to Target Data Testing

Source to Target Data Testing involves comparing the data in the source system with the data in the target system to ensure that all data has been correctly extracted, transformed, and loaded without any loss or corruption.

3. What is Data Profiling in ETL testing?

Choose one option

a) Creating user profiles for data access
b) Analyzing source data to understand its content, structure, and quality
c) Profiling the performance of ETL jobs
d) Creating profiles of data warehouse users

Answer 3

b) Analyzing source data to understand its content, structure, and quality

This helps in identifying potential issues early in the ETL process and aids in designing appropriate transformation rules.

4. A performance test is conducted to determine if ETL systems can handle ____ at the same time.

Choose one option

a) Multiple Users
b) Transactions
c) Both a) and b)
d) None of the above

Answer 4

c) Both a) and b)

A performance test is conducted to determine if ETL systems can handle multiple users and transactions at the same time.

5. Which type of testing checks that all data from the source system is loaded into the target system without any missing records?

a) Performance Testing
b) Data Completeness Testing
c) Security Testing
d) Usability Testing

Answer 5

b) Data Completeness Testing

Data Completeness Testing verifies that all expected data is loaded from source systems to destination systems without any omissions.

6. Why is data profiling important in ETL testing?

Choose one option

a) It formats the output reports
b) It identifies issues in data quality before loading
c) It integrates with third-party tools
d) It enhances user interface

Answer 6

b) It identifies issues in data quality before loading

Data profiling helps in understanding data structures, quality, and ensuring data accuracy and consistency before loading.

7. In ETL, what is a common method for handling inconsistent data?

Choose one option

a) Data Archiving
b) Data Cleansing
c) Data Encryption
d) Data Mapping

Answer 7

b) Data Cleansing

Data cleansing involves procedures to correct or remove inaccurate, incomplete, and duplicate data to ensure data quality and consistency.

8. Before data is moved to the warehouse, the extracted data can be validated in the ____ area.

Choose one option

a) Staging
b) Staggering
c) Studying
d) None

Answer 8

a) Staging

Before data is moved to the warehouse, the extracted data can be validated in the staging area.

9. Which of the following is/are the method(s) to extract the data?

a) FULL Extraction
b) Partial Extraction – Without Update Notification
c) Partial Extraction – With Update Notification
d) All of the above

Answer 9

d) All of the above

10. Which of the following is/are the validation(s) using the extraction(s)?

a) Check the source data against the record
b) Ensure that the data type is correct
c) There will be a check to see if all the keys are there
d) All of the above

Answer 10

d) All of the above

11. Which of the following is/are the type(s) of loading?

Choose one option

a) Initial Load
b) Incremental Load
c) Full Refresh
d) All of the above

Answer 11

d) All of the above

12. With a ____, all tables are erased and reloaded with new information.

Choose one option

a) Full Load
b) Incremental Load
c) Full Refresh
d) All of the above

Answer 12

c) Full Refresh

With a Full Refresh, all tables are erased and reloaded with new information.

13. The term is ETL now extended to ____ or Extract, Monitor, Profile, Analyze, Cleanse, Transform, and Load.

Choose one option

a) E-MPAC-TL
b) E-PAC-TL
c) E-MAP-TL
d) E-MPAA-TL

Answer 13

a) E-MPAC-TL

The term is now extended to E-MPAC-TL or Extract, Monitor, Profile, Analyze, Cleanse, Transform, and Load.

14. In ____, analysis and validation of the data pattern and formats will be performed, as well as identification and validation of redundant data across data sources to determine the actual content, structure, and quality of the data.

Choose one option

a) Data Profiling
b) Data Analysis
c) Source Analysis
d) Cleansing

Answer 14

a) Data Profiling

In data profiling, analysis and validation of the data pattern and formats will be performed, as well as identification and validation of redundant data across data sources to determine the actual content, structure, and quality of the data.

15. ETL testing is also known as –

Choose one option

a) Table balancing
b) Product Reconciliation
c) Both a) and b)
d) None of the above

Answer 15

c) Both a) and b)

ETL testing is sometimes referred to as table balancing and product reconciliation as it involves ensuring that the data transferred from the source to the destination is accurate and consistent, essentially “balancing” or reconciling between systems.

16. Which tool is not typically used for ETL Testing?

Choose one option

a) Informatica
b) Apache JMeter
c) Oracle Data Integrator
d) Microsoft SSIS

Answer 16

b) Apache JMeter

JMeter is primarily used for performance testing, not specifically for ETL testing, which deals with data processes and transformations.

17. What does NULL value testing check for in ETL?

Choose one option

a) The presence of empty strings
b) The correct handling of NULL values during transformation
c) The speed of processing NULL values
d) The number of NULL values in the source data

Answer 17

b) The correct handling of NULL values during transformation

NULL value testing in ETL checks for the correct handling of NULL values during the transformation process. It ensures that NULL values are properly recognized, transformed, and loaded into the target system according to the defined business rules.

18. What is the purpose of Incremental ETL Testing?

a) To test only new or updated data since the last ETL run
b) To gradually increase the volume of test data
c) To test the ETL process in small increments
d) To incrementally improve the ETL process

Answer 18

a) To test only new or updated data since the last ETL run

Incremental ETL Testing is performed to test only the new or updated data since the last ETL run. This type of testing is crucial for ensuring that ongoing data updates are correctly processed and integrated into the target system without affecting existing data.

19. What is the main purpose of Performance Testing in ETL?

a) To test the user interface performance
b) To measure and optimize the speed and efficiency of ETL processes
c) To check the performance of database queries
d) To test the network performance

Answer 19

b) To measure and optimize the speed and efficiency of ETL processes

20. You are testing the ETL process for a financial institution that deals with sensitive customer data. What security measures should you consider during ETL testing to ensure data protection?

Choose one option

a) Implementing data encryption during extraction
b) Disabling firewalls to facilitate data flow
c) Using publicly accessible APIs for data transfer
d) Storing sensitive data in plain text format

Answer 20

a) Implementing data encryption during extraction

Implementing data encryption during extraction ensures the protection of sensitive data. This protection occurs while transferring data from source to target. It mitigates the risk of unauthorized access.

21. During ETL testing, you notice that duplicate records are being loaded into the target database. What ETL test scenario could help identify and prevent such occurrences?

Choose one option

a) Testing data transformations with small datasets
b) Testing with production-sized datasets
c) Testing data quality constraints
d) Testing data load performance

Answer 21

C) Testing data quality constraints

Testing data quality constraints, such as uniqueness constraints, can help identify and prevent the loading of duplicate records into the target database.

22. While testing the ETL process, you encounter a situation where the source system undergoes a schema change. How should you approach this situation in terms of ETL testing?

Choose one option

a) Ignore the schema change and proceed with testing
b) Pause testing until the schema change is reverted
c) Modify ETL mappings to accommodate the new schema
d) Notify the stakeholders and discontinue testing

Answer 22

c) Modify ETL mappings to accommodate the new schema

23. You are conducting ETL testing on a procedure that involves transferring data from a flat file into a database. However, the data loading stage is slower than anticipated, and the system resources are not being fully utilized. What measures could you take to enhance the performance of the data loading process?

Choose one option

a) Increase database server capacity
b) Optimize SQL queries
c) Increase the file size for faster loading
d) Disable data validation during loading

Answer 23

b) Optimize SQL queries

Optimizing SQL queries can significantly improve data loading performance by reducing query execution time. This can lead to better resource utilization and faster ETL processing.

24. While conducting ETL testing, you face a scenario where the source system has intermittent outages. How can you maintain data integrity and consistency despite these outages?

a) Pause the ETL process until the source system is stable
b) Implement retry mechanisms for data extraction
c) Skip the affected data during extraction
d) Disable error handling temporarily

Answer 24

b) Implement retry mechanisms for data extraction

Implementing retry mechanisms for data extraction helps ensure that data is eventually extracted successfully, even if the source system experiences intermittent outages. This helps maintain data integrity and consistency.

25. What distinguishes a dimensional data model used in ETL processes?

a) High normalization levels
b) Use of rows and columns
c) Use of fact and dimension tables
d) Complex security features

Answer 25

c) Use of fact and dimension tables

Dimensional models use fact and dimension tables to organize and represent data for analytical purposes effectively.

We would love to hear from you! Please leave your comments and share your scores in the section below

October 1, 2025April 17, 2026 vibssingh

ETL Testing – Multiple Choice Questions and Answers – MCQ1

Last Updated On

April 17, 2026

HOME

Welcome to the ETL Testing Quiz! This blog post features 25 multiple-choice questions that explore basic concepts of ETL Testing.

1. What is the full form of ETL?

a) Extract, Transformation and Load
b) Extract, Transformation and Lead
c) Extract, Transfusion and Load
d) Extract, Transfusion and Lead

Answer 1

a) Extract, Transformation and Load

2. To fetch data from one database and place it in another, ETL combines all ____ database functions into one tool.

a) One
b) Two
c) Three
d) Four

Answer 2

c) Three

To fetch data from one database and place it in another, ETL combines all three database functions into one tool.

3. What is the main purpose of ETL Testing?

a) To test application UI
b) To ensure data is extracted, transformed, and loaded correctly
c) To verify API endpoints
d) To check database installation

Answer 3

b) To ensure data is extracted, transformed, and loaded correctly

4. Which of the following is NOT an ETL tool?

Choose one option

a) Informatica
b) Talend
c) QlikView
d) DataStage

Answer 4

c) QlikView

QlikView is a reporting/visualization tool, not an ETL tool.

5. Data in ETL testing is usually extracted from

a) Flat files
b) Databases
c) APIs
d) All of the above

Answer 5

d) All of the above

6. In ETL testing, surrogate keys are

Choose one option

a) Natural business keys
b) System-generated unique identifiers
c) Duplicate keys
d) Encrypted passwords

Answer 6

b) System-generated unique identifiers

7. Getting information from a database is called ___

Choose one option

a) Extracting
b) Transforming
c) Loading
d) None

Answer 7

a) Extracting

8. The process of ____ data involves converting it from one form to another.

Choose one option

a) Extracting
b) Transforming
c) Loading
d) None

Answer 8

b) Transforming

9. Writing data into a database is called ___

a) Extracting
b) Transforming
c) Loading
d) None

Answer 9

c) Loading

10. ETL is often used to build a –

a) Data Center
b) Data Warehouse
c) Data Care Center
d) Data Set

Answer 10

b) Data Warehouse

11. In today’s environment, ETL is becoming more and more necessary for many reasons, including:

Choose one option

a) In order to make critical business decisions, companies use ETL to analyze their business data.
b) Data warehouses are repositories where data is shared.
c) In ETL, data is moved from a variety of sources into a data warehouse.
d) All of the above

Answer 11

d) All of the above

12. What is the main challenge in ETL Testing?

Choose one option

a) Verifying UI elements
b) Handling large volumes of data
c) Testing mobile devices
d) Validating screen layouts

Answer 12

b) Handling large volumes of data

13. Which is a popular open-source ETL tool?

Choose one option

a) Informatica
b) Talend
c) DataStage
d) Ab Initio

Answer 13

b) Talend

14. In ETL testing, reconciliation reports are used for

Choose one option

a) Matching UI data
b) Comparing source and target data counts
c) API validation
d) Security audit

Answer 14

b) Comparing source and target data counts

15. What is Incremental Load in ETL?

Choose one option

a) Loading full data every time
b) Loading only new/changed records
c) Reloading only primary keys
d) Reloading metadata only

Answer 15

b) Loading only new/changed records

16. What does CDC stand for in ETL?

Choose one option

a) Change Data Capture
b) Central Data Collection
c) Clean Data Conversion
d) Core Data Copy

Answer 16

a) Change Data Capture

17. Which SQL command is used to modify existing data in a table?

Choose one option

a) Alter
b) Update
c) Modify
d) Change

Answer 17

b) Update

The UPDATE statement is used to modify existing data in a table based on specified conditions.

18. You are testing an ETL process that extracts customer data from a source system and loads it into a data warehouse. During testing, you notice that some customer records have not been properly transformed, resulting in missing information. What could be the potential causes of this issue?

a) Inaccurate data mapping
b) Transformation logic errors
c) Data type mismatches
d) Insufficient data profiling

Answer 18

a) Inaccurate data mapping

19. While testing an ETL process, you encounter duplicate records in the target database. What strategies can you employ to identify and eliminate these duplicates?

a) Implement deduplication logic in the transformation phase
b) Utilize SQL queries with DISTINCT keyword
c) Perform data profiling to identify duplicate patterns
d) Leverage hashing algorithms for record comparison

Answer 19

a) Implement deduplication logic in the transformation phase and c) Perform data profiling to identify duplicate patterns

20. During ETL testing, you encounter data quality issues, such as missing values and inconsistencies. How can you ensure data quality is maintained throughout the ETL process?

Choose one option

a) Implement data validation checks at each stage
b) Use data profiling to identify anomalies
c) Perform data cleansing before transformation
d) Employ referential integrity constraints

Answer 20

a) Implement data validation checks at each stage

21. Which is NOT a challenge in ETL testing?

Choose one option

a) Large volume of data
b) Data quality issues
c) Testing across multiple systems
d) GUI responsiveness

Answer 21

d) GUI responsiveness

22. Which of the following checks record counts between source and target?

Choose one option

a) Data Completeness Testing
b) Data Transformation Testing
c) Regression Testing
d) Negative Testing

Answer 22

a) Data Completeness Testing

23. Data transformation in ETL testing may include

Choose one option

a) Aggregations
b) Data type conversions
c) Business rule application
d) All of the above

Answer 23

d) All of the above

24. A star schema consists of

a) Fact table and dimension tables
b) Only fact tables
c) Only dimension tables
d) Normalized tables

Answer 24

a) Fact table and dimension tables

25. In ETL testing, ‘mapping document’ is used to

a) Define schema design
b) Describe transformation rules
c) Maintain test cases
d) Automate test execution

Answer 25

b) Describe transformation rules

We would love to hear from you! Please leave your comments and share your scores in the section below

September 29, 2025 vibssingh

Java – Multiple Choice Questions and Answers – Strings

Last Updated On

HOME

Welcome to the Java Quiz! This blog post features 25 multiple-choice questions that explore the concepts of Strings in Java.

1. What is the primary characteristic of strings in Java?

a) Mutable
b) Immutable
c) Dynamic
d) External

Answer 1

b) Immutable

Strings in Java are immutable, meaning their values cannot be changed once created.

2. What is the correct way to declare a String in Java?

a) String str = ‘Hello’;
b) String str = new String(“Hello”);
c) String str = String(“Hello”);
d) String str = Hello;

Answer 2

b) String str = new String(“Hello”);

Strings in Java are declared using String str = new String(“Hello”); or simply String str = “Hello”;.

3. What is the default value of an element in an int array in Java?

Choose one option

a) 1
b) 0
c) null
d) Undefined

Answer 3

b) 0

In Java, arrays of primitive types like int are initialized to their default values. The default value for int is 0

4. What will be the output of the following Java program?

class Test
    {
        public static void main(String args[]) 
        {
            int array_variable [] = new int[10];
	        for (int i = 0; i < 10; ++i) 
            {
                array_variable[i] = i;
                System.out.print(array_variable[i] + " ");
                i++;
            }
        } 
   }

Choose one option

a) 0 2 4 6 8
b) 1 3 5 7 9
c) 0 1 2 3 4 5 6 7 8 9
d) 1 2 3 4 5 6 7 8 9 10

Answer 4

a) 0 2 4 6 8

5. Why are Strings immutable in Java?

a) To improve performance
b) To allow modifications in-place
c) To ensure thread safety and security
d) Because Java does not support mutable objects

Answer 5

c) To ensure thread safety and security

String immutability ensures that once created, a String cannot be modified, making it thread-safe and secure.

6. What will be the output of the following Java program?

public class Test {
    
    public static void main(String args[]) {
        String obj = "I" + "like" + "Java";
        System.out.println(obj);
    }
}

Choose one option

a) I
b) like
c) Java
d) IlikeJava

Answer 6

d) IlikeJava

Java defines an operator +, it is used to concatenate strings.

7. What will be the output of the following Java program?

public class Test {
    
    public static void main(String args[]) {
        String obj = "I LIKE JAVA";
        System.out.println(obj.charAt(3));
    }
}

Choose one option

a) I
b) L
c) K
d) E

Answer 7

a) I

charAt() is a method of class String which gives the character specified by the index. obj.charAt(3) gives 4th character

8. What will be the output of the following Java program?

public class Test {

    public static void main(String args[]) {
        String obj = "I LIKE JAVA";
        System.out.println(obj.length());
    }
}

Choose one option

a) 9
b) 10
c) 11
d) 12

Answer 8

c) 11

The string “I LIKE JAVA” contains 11 characters, including the spaces. The length() method returns the total number of characters in the string. So, the output is 11.

9. What will be the output of the following Java program?

public class Test {

    public static void main(String args[]) {
        String obj = "hello";
        String obj1 = "world";
        String obj2 = obj;
        obj2 = " world";
        System.out.println(obj + " " + obj2);
    }
}

a) hello hello
b) world world
c) hello world
d) world hello

Answer 9

c) hello world

This is the standard way of declaring an array of strings in Java.

10. Which of the following is a valid declaration and initialization of String array in Java

public class Test {

    public static void main(String args[]) {
        String obj = "hello";
        String obj1 = "world";
        String obj2 = "hello";
        System.out.println(obj.equals(obj1) + " " + obj.equals(obj2));
    }
}

a) false false
b) true true
b) true false
d) false true

Answer 10

d) false true

equals() is method of class String, it is used to check equality of two String objects, if they are equal, true is retuned else false.

11. What will be the output?

public class Test {

    public static void main(String args[]) {
        System.out.println("Hello World".indexOf('W'));
    }
}

Choose one option

a) 0
b) 5
c) 6
d) -1

Answer 11

c) 6

The indexOf() method returns the index of the first occurrence of the specified character.

12. How do you compare two strings in Java?

Choose one option

a) ==
b) equals()
c) compareTo()
d) Both b) and c)

Answer 12

d) Both b) and c)

Use equals() for value comparison and compareTo() for lexicographical order.

13. Which of the following will return a substring from a string?

Choose one option

a) str.sub()
b) str.substring()
c) str.slice()
d) str.split()

Answer 13

b) str.substring()

The substring() method extracts a substring from the string.

14. What is printed by the following code snippet?

public class Test {

    public static void main(String args[]) {
        System.out.println("Java".compareTo("Java"));
    }
}

Choose one option

a) 0
b) 1
c) -1
d) Compilation error

Answer 14

a) 0

The compareTo() method returns 0 if the two strings are equal.

15. What will be the result of this expression?

public class Test {

    public static void main(String args[]) {
        System.out.println("abc".substring(1, 3));
    }
}

Choose one option

a) ab
b) abc
c) bc
d) a

Answer 15

c) bc

The substring(start, end) method returns the substring from start index to end-1.

16. How can you check if a string is empty?

Choose one option

a) str.isEmpty()
b) str.length() == 0
c) Both a) and b)
d) str.equals(“”)

Answer 16

c) Both a) and b)

Both methods can be used to check if a string is empty.

17. What does the StringBuilder class do?

Choose one option

a) It creates immutable strings.
b) It creates mutable strings.
c) It converts strings to numbers.
d) It is not a class in Java.

Answer 17

b) It creates mutable strings.

StringBuilder allows for the creation of mutable strings, which can be modified.

18. Which method would you use to split a string into an array based on a delimiter?

a) split()
b) divide()
c) slice()
d) substring()

Answer 18

a) split()

The split() method splits a string into an array based on a specified delimiter.

19. Which of the following will convert a string to a number?

a) parseInt()
b) valueOf()
c) toNumber()
d) Both a) and b)

Answer 19

d) Both a) and b)

Both parseInt() and valueOf() can convert a string to a number.

20. What is the output of the following code?

public class Test {

    public static void main(String args[]) {
        System.out.println("abc".repeat(3));
    }
}

Choose one option

a) abcabcabc
b) abc abc abc
c) abcabc abc
d) Compilation Error

Answer 20

a) abcabcabc

The repeat(int) method returns a string whose value is the concatenation of the specified string repeated the given number of times.

21. What is the output of the following code?

public class Test {

    public static void main(String args[]) {
        System.out.println("Hello".replace('e', 'a'));
    }
}

Choose one option

a) Hallo
b) Hello
c) Halla
d) Hella

Answer 21

a) Hallo

The replace() method replaces the specified character with another character.

22. What will be the output of the following program

public class Test {

    public static void main(String args[]) {
        String s1 = new String("Hello");
        String s2 = new String("Hello");
        System.out.println(s1 == s2);
    }
}

Choose one option

a) true
b) false
c) Compilation error
d) Runtime error

Answer 22

b) false

The == operator compares object references, not values. Since s1 and s2 are two different objects, it returns false.

23. Which of these methods can be used to check if two strings are equal, ignoring case considerations?

Choose one option

a) equals()
b) equalsIgnoreCase()
c) compareTo()
d) compareIgnoreCase()

Answer 23

b) equalsIgnoreCase()

The equalsIgnoreCase() method compares two strings, ignoring case differences.

24. What will be the result if you try to modify an existing string?

a) The string will be changed
b) A new string will be created
c) An exception will be thrown
d) Compilation error

Answer 24

b) A new string will be created

Strings in Java are immutable, so any modification creates a new string.

25. Which method checks if a string starts with a specified prefix?

a) beginsWith()
b) start()
c) startsWith()
d) prefix()

Answer 25

c) startsWith()

The startsWith() method checks if the string begins with the specified prefix.

We would love to hear from you! Please leave your comments and share your scores in the section below

September 26, 2025September 26, 2025 vibssingh

Java – Multiple Choice Questions and Answers – Inheritance & Polymorphism

Last Updated On

September 26, 2025

HOME

Welcome to the Java Quiz! This blog post features 25 multiple-choice questions that explore the concepts of Inheritance & Polymorphism in Java.

1. What is inheritance in Java?

a) A mechanism where one class acquires the properties of another
b) A way to allow multiple classes to have the same method names
c) A class that implements an interface
d) None of the above

Answer 1

a) A mechanism where one class acquires the properties of another

2. Which keyword is used for inheritance in Java?

a) implements
b) extends
c) inherits
d) uses

Answer 2

b) extends

The extends keyword is used to indicate that a class is inheriting from another class.

3. What will be the output of the following Java code?

 class Apple {
       public void print() { System.out.println("Apple"); }
   }
   class Banana extends Apple {
       public void print() { System.out.println("Banana"); }
   }
   public class Test {
       public static void main(String[] args) {
           Apple  apple = new Banana();
           apple.print();
       }
   }

Choose one option

a) Apple
b) Banana
c) No Output
d) Compilation Error

Answer 3

b) Banana

This is an example of dynamic method dispatch (polymorphism). The type of the object, not the reference type, determines which method is called.

4. If a class extends another class, which of the following members are inherited?

Choose one option

a) Only public methods
b) Public and protected members
c) Private methods
d) All members including private

Answer 4

b) Public and protected members

A subclass can inherit public and protected members of the superclass but not private members.

5. Which of these is correct way of inheriting class A by class B?

a) class B + class A {}
b) class B inherits class A {}
c) class B extends A {}
d) class B extends class A {}

Answer 5

c) class B extends A {}

The correct syntax for inheritance in Java is class B extends A {}. The extends keyword is used, and we refer to the superclass by name, not with the keyword class.

6. What will be the output of the following Java program?

 class Apple {
       public void print() { System.out.println("Apple"); }
   }
   class Banana extends Apple {
       public void print() { System.out.println("Banana"); }
   }
   public class Test {
       public static void main(String[] args) {
           Apple  apple = new Apple();
           apple.print();
       }
   }

Choose one option

a) Apple
b) Banana
c) No Output
d) Compilation Error

Answer 6

a) Apple

7. What will be the output of the following Java program?

class A {
    A(int x) { }
}

class B extends A {
    B(int x) {
        System.out.println("Constructor B");
    }
}

public class Test {
    public static void main(String[] args) {
        B obj = new B(10);
    }
}

Choose one option

a) It compiles without error.
b) It causes a compilation error.
c) It throws a runtime error.
d) It prints “Constructor B”

Answer 7

b) It causes a compilation error.

The constructor in B needs to explicitly call the constructor of A using super(x). This is required because A doesn’t have a no-argument constructor.

8. What will be the output?

class Parent {
    void method() {
        System.out.println("Parent method");
    }
}

class Child extends Parent {
}

public class Test {
    public static void main(String[] args) {
        Child obj = new Child();
        obj.method();
    }
}

Choose one option

a) Parent method
b) Child method
c) Compilation Error
d) Runtime Error

Answer 8

a) Parent method

Child doesn’t override method(), it inherits method() from Parent.

9. Which of the following statements about inheritance is false?

a) Java supports single inheritance.
b) Java allows multiple class inheritance using extends.
c) Interfaces can be used to achieve multiple inheritance.
d) The super keyword can be used to invoke the parent class constructor.

Answer 9

b) Java allows multiple class inheritance using extends.

Java does not allow multiple class inheritance using extends to avoid ambiguity issues. Instead, interfaces provide an alternative for multiple inheritance.

10. Which type of inheritance is demonstrated when a class inherits from a class that already inherits from another class?

a) Single inheritance
b) Multiple inheritance
c) Multilevel inheritance
d) Hierarchical inheritance

Answer 10

c) Multilevel inheritance

The type of inheritance demonstrated when a class inherits from a class that already inherits from another class is called multilevel inheritance. In this type of inheritance, a class is derived from a derived class, effectively creating a hierarchy of classes.

11. What is the keyword used in Java to prevent a class from being inherited?

Choose one option

a) abstract
b) final
c) static
d) private

Answer 11

b) final

The final keyword in Java is used to prevent a class from being inherited. When a class is declared as final, it cannot be extended by any other class.

12. What is the purpose of using the `super` keyword in Java?

Choose one option

a) To create a new object instance
b) To call a constructor of the subclass
c) To refer to the current object’s superclass
d) To hide inherited methods

Answer 12

c) To refer to the current object’s superclass

The super keyword is used to access the superclass’s constructor or methods and can be used to invoke the superclass version of an overridden method.

13. Which of the following statements about the super keyword in Java is true?

Choose one option

a) The super keyword is used to call the parent class constructor.
b) The super keyword is used to access the methods and properties of the parent class.
c) The super keyword is used to create an instance of a child class.
d) The super keyword is not supported in Java.

Answer 13

b) The super keyword is used to access the methods and properties of the parent class.

The super keyword in Java is used to access the methods and properties of the parent class. It is often used to invoke the overridden methods of the parent class in the child class.

14. What will be the output of the following code?

  class Parent {
    public void print() {
        System.out.println("Parent");
    }
}

class Child extends Parent {
    public void print() {
        System.out.println("Child");
        super.print();
    }
}

public class Main {
    public static void main(String[] args) {
        Child child = new Child();
        child.print();
    }
}

Choose one option

a) Parent
Child
b) Child
Parent
c) Parent
d) Child

Answer 14

b) Child
Parent

This exception is thrown when a program attempts to use an object reference that has not been properly initialized.

15. What will be the result of the following code?

package pack1;
public class A {
    public void display() {
        System.out.println("Hello from A");
    }
}

package pack2;
import pack1.A;
public class B {
    public static void main(String args[]) {
        A obj = new A();
        obj.display();
    }
}

Choose one option

a) No output
b) Hello from A
c) Compiler error
d) Runtime error

Answer 15

b) Hello from A

Since class A is public and properly imported in pack2, there is no issue accessing it.

16. What is the result of the following code snippet?

class A 
    {
        int i;
        void display() 
        {
            System.out.println(i);
        }
    }    

    class B extends A 
    {
        int j;
        void display() 
        {
            System.out.println(j);
        }
    }    
    
   class Test
    {
        public static void main(String args[])
        {
            B obj = new B();
            obj.i=1;
            obj.j=2;   
            obj.display();     
        }
   }

Choose one option

a) 0
b) 1
c) 2
d) Compilation Error

Answer 16

c) 2

Class A & class B both contain display() method, class B inherits class A, when display() method is called by object of class B, display() method of class B is executed rather than that of Class A.

17. What will be printed?

 class A 
    {
        int i;
    }    

    class B extends A 
    {
        int j;
        void display() 
        {
            super.i = j + 1;
            System.out.println(j + " " + i);
        }
    }    

    class Test 
    {
        public static void main(String args[])
        {
            B obj = new B();
            obj.i=1;
            obj.j=2;   
            obj.display();     
        }
   }

Choose one option

a) Hello
a) 2 2
b) 3 3
c) 2 3
d) 3 2

Answer 17

c) 2 3

Class A and Class B both contain a display() method. Class B inherits Class A. When the display() method is called by an object of Class B, the display() method of Class B is executed rather than that of Class A. The value of i is updated in the display() method using the super keyword.

18. What is polymorphism in Java?

a) A feature that allows a class to be abstract
b) A feature that allows one interface to be used for a general class of actions
c) A type of inheritance in Java
d) A way to modularize the code

Answer 18

b) A feature that allows one interface to be used for a general class of actions

Polymorphism allows methods to do different things based on the object it is acting upon, using a general interface for different underlying forms (data types).

19. How can you achieve polymorphism in Java?

a) By method overloading only
b) By method overriding only
c) By both method overloading and overriding
d) By using final classes

Answer 19

c) By both method overloading and overriding

Polymorphism can be achieved through method overloading (compile-time polymorphism) and method overriding (run-time polymorphism).

20. Which of the following statements about multiple inheritance of interfaces is true?

Choose one option

a) It is allowed in Java
b) It is not allowed in Java
c) It leads to ambiguity
d) Only one interface can be inherited

Answer 20

a) It is allowed in Java

Java allows a class to implement multiple interfaces, enabling multiple inheritance of method signatures.

21. What is the output of the below program?

public class Parent {
    void m1(String x) {
        System.out.println("One");
    }
}

public class Derived extends Parent{
    public void m1(String x) {
        System.out.println("Two");
        super.m1(null);
    }
}

public class Test {
    public static void main(String[] args){
        Parent obj = new Derived();
        obj.m1(null);
    }
}

a) Two, One
b) One, Two
c) Compiler error
d) Runtime error

Answer 21

a) Two, One

The m1 method of Derived is executed first because Derived overrides m1. It prints “Two”. Then, super.m1(null) is executed within the m1 method of Derived, which calls the m1 method of the Parent class, printing “One”.

22. What will be the output of this program?

public class Test{

    void m1(String x){
        System.out.println("One");
    }
    
    protected void m1(String x, String y){
        System.out.println("Two");
    }
    
    public static void main(String[] args){
        Test obj = new Test();
        obj.m1("ABC");
        obj.m1("PQR", "XYZ");
    }
}

a) Two One
b) One Two
c) Compile time error
d) Runtime error

Answer 22

b) One Two

23. What is the output of the following program?

public class PolymorphismDemoClass {
    void add(int x, int y){
        System.out.println("1. Addition is: " +(x+y));
    }
    
   void add(int y, int x){
        System.out.println("2. Addition is: " +(x+y));
    }
    
   public static void main(String[] args){
        PolymorphismDemoClass obj = new PolymorphismDemoClass();
        obj.add(20, 30);
    }
}

a) Prints 2. Addition of two numbers: 50
b) Prints 1. Addition of two numbers: 50
c) Compile time error
d) Runtime error

Answer 23

c) Compile time error

24. What is the key difference between compile-time and runtime polymorphism in Java?

a) Compile-time polymorphism is implemented using method overriding, while runtime polymorphism is implemented using method overloading.
b) Compile-time polymorphism is determined during compilation, while runtime polymorphism is resolved at runtime.
c) Runtime polymorphism is faster than compile-time polymorphism.
d) Compile-time polymorphism is achieved using interfaces.

Answer 24

b) Compile-time polymorphism is determined during compilation, while runtime polymorphism is resolved at runtime.

Compile-time polymorphism (method overloading) is resolved at compile-time, while runtime polymorphism (method overriding) is determined during execution via dynamic method dispatch.

25. What will happen if two classes in different packages have the same name and are imported in a Java file?

a) Compilation error due to ambiguity.
b) The last imported class is used.
c) The first imported class is used.
d) Java automatically renames one class.

Answer 25

a) Compilation error due to ambiguity.

Java does not allow ambiguity in class names across packages. Fully qualified names must be used in such cases.

We would love to hear from you! Please leave your comments and share your scores in the section below

September 24, 2025September 24, 2025 vibssingh

Java – Multiple Choice Questions and Answers – Exception Handling

Last Updated On

September 24, 2025

HOME

Welcome to the Java Quiz! This blog post features 25 multiple-choice questions that explore the exception handling in Java.

1. What is Exception in Java

a) An error that occurs during runtime
b) An error that occurs during compilation
c) A warning issued by the compiler
d) A type of loop

Answer 1

a) An error that occurs during runtime

2. Which of the following is the root class of the exception hierarchy in Java?

a) Exception
b) Throwable
c) Error
d) RuntimeException

Answer 2

b) Throwable

The root class of the Java exception hierarchy is Throwable. Both Exception and Error are subclasses of Throwable.

3. What will be the output of the following Java code?

public class QAAutomation {
    
     public static void main(String[] args) {
        try {
            System.out.println("Inside try");
            throw new RuntimeException("Error");
        } finally {
            System.out.println("Inside finally");
        }
    }
}

Choose one option

a) Inside try
b) Inside try Inside finally
c) Inside try Inside finally RuntimeException
d) Compilation Error

Answer 3

c) Inside try Inside finally RuntimeException

The finally block executes even after an exception is thrown.

4. What will be the output of the following Java program?

 public class QAAutomation {
    
    static void method() throws Exception {
        throw new Exception("Error occurred");
    }

    public static void main(String[] args) {
        method();
    }
}

Choose one option

a) Compilation Error
b) Runtime error
c) Exception: Error occurred
d) Program runs successfully

Answer 4

a) Compilation Error

The method() declares throws Exception, but main() does not handle it, leading to a compilation error.

5. What is the difference between throw and throws?

a) throw is used to declare exceptions, throws is used to throw exceptions
b) throws is used to declare exceptions, throw is used to throw exceptions
c) Both are used to declare exceptions
d) Both are used to throw exceptions

Answer 5

b) throws is used to declare exceptions, throw is used to throw exceptions

throw is used inside a method to throw an exception, while throws is used in the method signature to declare possible exceptions.

6. What will be the output of the following Java program?

 class CustomException extends Exception {
    public CustomException(String message) {
        super(message);
    }
}

public class Test {
    public static void main(String[] args) {
        try {
            throw new CustomException("Custom error occurred");
        } catch (CustomException e) {
            System.out.println(e.getMessage());
        }
    }
}

Choose one option

a) Custom error occurred
b) Compilation Error
c) No Output
d) Runtime Exception

Answer 6

a) Custom error occurred

A custom exception is thrown and caught, and e.getMessage() prints the error message.

7. What will be the output of the following Java program?

public class Test {
    
    public static void main(String args[]) {
        try {
            int a, b;
            b = 0;
            a = 5 / b;
            System.out.print("A");
        } catch (ArithmeticException e) {
            System.out.print("B");
        } finally {
            System.out.print("C");
        }
    }
}

Choose one option

a) A
b) B
c) AC
d) BC

Answer 7

d) BC

The variable a is set to 0, in expression b = 5/a refers to dividing an int{5} with an int{0} which results in an ArithmeticException, which is caught by the catch statement and “B” is printed. Since the final block must be executed in any case . Hence “C” also prints after “B”.

8. What will be the output of the following Java program?

public class Test {
    public static void main(String args[])
    {
        try
        {
            int i, sum;
            sum = 10;
            for (i = -1; i < 3 ;++i)
                sum = (sum / i);
        }
        catch(ArithmeticException e)
        {
            System.out.print("0");
        }
        System.out.print(sum);
    }
}

Choose one option

a) 0
b) 05
c) Compilation Error
d) Runtime Error

Answer 8

c) Compilation Error

sum variable is declared in try block, but trying to access it outside the try-catch block.

9. Which of the following can be declared in a method’s `throws` clause?

a) RuntimeException
b) Error
c) IOException
d) None of the above

Answer 9

c) IOException

Checked exceptions like IOException must be declared in a method’s throws clause if not caught. RuntimeException and Error are typically not declared.

10. What happens if an exception is not caught in a Java program?

a) The program continues running as normal
b) The program stops execution
c) The exception is ignored
d) None of the above

Answer 10

b) The program stops execution

If an exception is not caught, program execution will halt, and the JVM will likely display an error message.

11. What will be the output?

public class Test{
    public static void main(String[] args) {
        try {
            System.exit(0);
        } finally {
            System.out.println("Finally executed");
        }
    }
}

Choose one option

a) Finally executed
b) No Output
c) Runtime Error
d) Compilation Error

Answer 11

b) No Output

System.exit(0) terminates the JVM, so the finally block does not execute.

12. How many catch blocks can be associated with one try block?

Choose one option

a) Only one
b) One or more
c) None
d) Exactly two.

Answer 12

b) One or more

A try block can have multiple catch blocks to handle different types of exceptions.

13. Which block is always executed whether an exception is handled or not?

Choose one option

a) try
b) catch
c) finally
d) throw

Answer 13

c) finally

The finally block is always executed after the try and catch blocks, regardless of whether an exception was handled.

14. What will be the output of the following code?

  public class Test {
         public static void main(String[] args) {
             String str = null;
             try {
                 System.out.println(str.length());
             } catch (NullPointerException e) {
                 System.out.println("Caught a NullPointerException");
             }
         }
     }

Choose one option

a) NullPointerException
b) Caught a NullPointerException
c) IllegalArgumentException
d) IOException

Answer 14

b) Caught a NullPointerException

This exception is thrown when a program attempts to use an object reference that has not been properly initialized.

15. What will be the result of this expression?

import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class Test {
    public static void readFile() throws IOException {
        File file = new File("example.txt");
        FileReader reader = new FileReader(file);
        reader.close();
    }

    public static void main(String[] args) {
        try {
            readFile();
        } catch (IOException e) {
            System.out.println("IOException handled");
        }
    }
}

Choose one option

a) RuntimeException
b) NullPointerException
c) IOException handled
d) ArithmeticException

Answer 15

c) IOException handled

Checked exceptions, such as IOException, must be declared or handled explicitly.

16. What is the result of the following code snippet?

public class Test {
    
    public static void main(String[] args) {

        try {
            int[] numbers = {1, 2, 3};
            System.out.println(numbers[3]);
            int division = 10 / 0;
        } catch (ArrayIndexOutOfBoundsException e) {
            System.out.println("Array index is out of bounds");
        } catch (ArithmeticException e) {
            System.out.println("Cannot divide by zero");
        } finally {
            System.out.println("Finally block executed");
        }
        System.out.println("Rest of the program");
    }
}

Choose one option

a) Array index is out of bounds
Finally block executed
Rest of the program

b) Cannot divide by zero
Finally block executed
Rest of the program

c) Finally block executed
Cannot divide by zero
Rest of the program

d) Cannot divide by zero
Rest of the program

Answer 16

a) Array index is out of bounds
Finally block executed
Rest of the program

The code tries to access the fourth element (index 3) of a three-element array, which causes an ArrayIndexOutOfBoundsException. This is caught by the first catch block, which prints “Array index is out of bounds.” The finally block is always executed, so “Finally block executed” is printed next. The program then continues with “Rest of the program.”

17. What will be the output of the below program?

public class Test {
    public static void main(String args[])
    {
        try
        {
            System.out.print("Hello" + " " + 1 / 0);
        }
        catch(ArithmeticException e)
        {
            System.out.print("World");
        }
    }
}

Choose one option

a) Hello
b) World
c) HelloWorld
d) Hello World

Answer 17

b) World

System.out.print() function first converts the whole parameters into a string and then prints, before “Hello” goes to output stream 1 / 0 error is encountered which is cached by catch block printing just “World”.

18. What does the `throws` keyword do?

a) It throws an exception
b) It declares that a method can throw exceptions
c) It defines a new exception
d) None of the above

Answer 18

b) It declares that a method can throw exceptions

The throws keyword is used in a method signature to declare that the method can throw specified exceptions.

19. Which exception is thrown when an object is attempted to be cast into a subclass it is not an instance of?

a) IllegalArgumentException
b) IndexOutOfBoundsException
c) ClassCastException
d) ClassNotFoundException

Answer 19

c) ClassCastException

ClassCastException is thrown to indicate that the code has attempted to cast an object to a class of which it is not an instance.

20. What is the output of the following code?

public class Test {

    public static void main(String[] args) {
        try {
            throw new Exception("First Exception");
        } catch (Exception e) {
            try {
                throw new Exception("Second Exception");
            } catch (Exception ex) {
                System.out.println(ex.getMessage());
            }
        }
    }
}

Choose one option

a) First Exception
b) Second Exception
c) First Exception followed by Second Exception
d) Second Exception followed by First Exception

Answer 20

b) Second Exception

The code throws the first exception, catches it, and then throws the second exception, which is caught and its message is printed.

21. What is the output of the below program?

public class Test {
    public static void main(String[] args) {
        try {
            throw new Error("Fatal error");
        } catch (Exception e) {
            System.out.println("Exception");
        } catch (Error e) {
            System.out.println("Error");
        }
    }
}

a) Exception
b) Error
c) Compiler error
d) The code will not compile.

Answer 21

b) Error

The code explicitly throws an Error with the message “Fatal error”. Since Error is a subclass of Throwable, it matches the catch block for Error, and “Error” is printed.

22. What will be the output of the below program?

public class Test {
    public static void main(String[] args) {
        try {
            int[] array = new int[5];
            System.out.println(array[5]);
        } catch (ArrayIndexOutOfBoundsException e) {
            System.out.println("ArrayIndexOutOfBoundsException");
        } finally {
            System.out.println("Finally block executed.");
        }
    }
}

a) ArrayIndexOutOfBoundsException
Finally block executed.
b) ArrayIndexOutOfBoundsException
c) Finally block executed.
d) The code will not compile.

Answer 22

a) ArrayIndexOutOfBoundsException
Finally block executed.

The code attempts to access an element at index 5 in the array which is not available. Hence it raises an ArrayIndexOutOfBoundsException. The catch block is executed, and then the finally block is executed.

23. What is the output of the following program?

public class Test {
    public static void main(String[] args) {
        try {
            throw new NullPointerException();
        } catch (RuntimeException e) {
            System.out.println("RuntimeException");
        } catch (Exception e) {
            System.out.println("Exception");
        }
    }
}

a) RuntimeException
b) Exception
c) NullPointerException
d) The code will not compile.

Answer 23

a) RuntimeException

The code explicitly throws a NullPointerException, which is a subclass of RuntimeException. Since the catch block for RuntimeException is defined first, it is executed.

24. Which of the following is true about custom exceptions?

a) Custom exceptions cannot extend Exception class
b) Custom exceptions are always checked exceptions
c) Custom exceptions can extend Exception or RuntimeException
d) Custom exceptions do not require a constructor

Answer 24

c) Custom exceptions can extend Exception or RuntimeException

Custom exceptions can extend Exception (checked) or RuntimeException (unchecked).

25. Which of the following exception must be either caught or declared to be thrown in Java?

a) NullPointerException
b) ArrayIndexOutOfBoundsException
c) FileNotFoundException
d) ArithmeticException

Answer 25

c) FileNotFoundException

FileNotFoundException is a checked exception in Java, hence it must be either caught or declared to be thrown.

We would love to hear from you! Please leave your comments and share your scores in the section below

September 22, 2025October 13, 2025 vibssingh

JAVA – Multiple Choice Questions and Answers

Last Updated On

October 13, 2025

HOME

Java – Multiple Choice Questions and Answers – Basic Java – NEW

Java – Multiple Choice Questions and Answers – Method, Overloading, Overriding – NEW

Java – Multiple Choice Questions and Answers – Exception Handling – NEW

Java – Multiple Choice Questions and Answers – Strings – NEW

Java – Multiple Choice Questions and Answers – Arrays – NEW

Java – Multiple Choice Questions and Answers – Inheritance & Polymorphism – NEW

QA Automation Expert

Automation solutions to build Test Framework

Author: vibssingh

How to create and write JSON with JSON.simple in Java

Write Simple JSON to File using JSON.simple

Write Complex JSON to File using JSON.simple

Java – Multiple Choice Questions and Answers – Arrays

How to Read JSON with JSON.simple

Read Simple JSON from File using JSON.simple

Read Complex JSON from File using JSON.simple

A Complete Guide to ETL Testing

What is ETL (Extract, Transform, Load)

What is ETL testing and why do we need it?

Stages of ETL Testing LifeCycle

Different types of testing involved in an ETL process

Various ETL Testing Tools

ETL testing challenges

ETL Testing – Multiple Choice Questions and Answers – MCQ2

ETL Testing – Multiple Choice Questions and Answers – MCQ1

Java – Multiple Choice Questions and Answers – Strings

Java – Multiple Choice Questions and Answers – Inheritance & Polymorphism

Java – Multiple Choice Questions and Answers – Exception Handling

JAVA – Multiple Choice Questions and Answers