Java Exercises - Basic to Advanced Java Practice Programs with Solutions

Looking for Java exercises to test your Java skills, then explore our topic-wise Java practice exercises? Here you will get 25 plus practice problems that help to upscale your Java skills.

As we know Java is one of the most popular languages because of its robust and secure nature. But, programmers often find it difficult to find a platform for Java Practice Online. In this article, we have provided Java Practice Programs. That covers various Java Core Topics that can help users with Java Practice.

So, with ado further take a look at our free Java Exercises to practice and develop your Java programming skills. Our Java programming exercises Practice Questions from all the major topics like loops, object-oriented programming, exception handling, and many more.

Java Practice Programs

This Java exercise is designed to deepen your understanding and refine your Java coding skills, these programs offer hands-on experience in solving real-world problems, reinforcing key concepts, and mastering Java programming fundamentals. Whether you're a beginner who looking to build a solid foundation or a professional developer aiming to sharpen your expertise, our Java practice programs provide an invaluable opportunity to sharpen your craft and excel in Java programming language .

Java enthusiasts can also benefit from practicing various java exercises on the GeeksforGeeks Online Practice Platform, where challenges cater to both beginners and advanced programmers.

1. Write Hello World Program in Java

The solution to the Problem is mentioned below:

// Java Program to Print
// Hello World
import java.io.*;

// Driver Class
class GFG {
    // main function
    public static void main(String[] args)
    {

        // Printing Hello World
        System.out.println("Hello World!");
    }
}

Hello World!

2. Write a Program in Java to Add two Numbers.

Input: 2 3
Output: 5

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3. Write a Program to Swap Two Numbers

Input: a=2  b=5
Output: a=5  b=2

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4. Write a Java Program to convert Integer numbers and Binary numbers.

Input: 9 
Output: 1001

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5. Write a Program to Find Factorial of a Number in Java.

Input: 5
Output: 120

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6. Write a Java Program to Add two Complex Numbers.

Input:   1+2i
             4+5i
Output: 5+7i

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7. Write a Program to Calculate Simple Interest in Java

Input :  P = 10000  R = 5  T = 5
Output : 2500

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8. Write a Program to Print the Pascal's Triangle in Java

Input : N = 5
Output:
          1
        1   1
      1   2   1
    1   3   3   1
  1   4   6   4   1
1   5   10   10   5   1

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9. Write a Program to Find Sum of Fibonacci Series Number

Input: n = 4
Output: 33
Explaination: Sum of numbers at even indexes = 0 + 1 + 3 + 8 + 21 = 33.

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Java Exercise on Pattern

10. Write a Program to Print Pyramid Number Pattern in Java.

    *
   ***
  *****
 *******

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11. Write a Java Program to Print Pattern.

* * * * * * 
*         * 
*         * 
*         *
*         *
* * * * * *

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12. Write a Java Program to Print Pattern.

          1 
        2 1 2 
      3 2 1 2 3 
    4 3 2 1 2 3 4 
  5 4 3 2 1 2 3 4 5 
6 5 4 3 2 1 2 3 4 5 6 

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13. Java Program to Print Patterns.

     *
    ***
   *****
  *******
 *********
***********
 *********
  *******
   *****
    ***
     *

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Array Exercises in Java

14. Write a Java Program to Compute the Sum of Array Elements.

Input: [ 2, 4, 6, 7, 9]
Output: 28

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15. Write a Java Program to Find the Largest Element in Array

Input: [ 7, 2, 5, 1, 4]
Output: 7

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16. Write Java Program to Find the Tranpose of Matrix

Input: 
[ [ 1, 2, 3 ]
  [ 4, 5, 6 ]
  [ 7, 8, 9 ] ]
Output: 
[ [ 1, 4, 7]
  [ 2, 5, 8]
  [ 3, 6, 9] ]

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17. Java Array Program For Array Rotation

Input: arr[] = {1, 2, 3, 4, 5, 6, 7},  d = 2
Output:  3 4 5 6 7 1 2

Explaination: d=2 so 2 elements are rotated to the end of the array. So, 1 2 is rotated back
So, Final result: 3, 4, 5, 6, 7, 1, 2

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18. Java Array Program to Remove Duplicate Elements From an Array

Input: [ 1, 2, 2, 3, 3, 3, 4, 5 ]
Output: [ 1, 2, 3, 4, 5 ]

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19. Java Array Program to Remove All Occurrences of an Element in an Array

Input: array = [ 1, 2, 1, 3, 5, 1 ] , key = 1
Output: [2, 3, 5]

Explaination: all the occurrences of element 1 is removed from the array So, array becomes from
[ 1, 2, 1, 3, 5, 1 ]  to
Final result: [2, 3, 5]

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String Exercises in Java

20. Java program to check whether a string is a Palindrome

Input: "racecar"
Output: Yes

Explaination: As racerar after reversing becomes racecar. As Reverse of String is same as String so it is Palindrome

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21. Java String Program to Check Anagram

Input: str1 = "Silent"
            str2 ="Listen"
Output: Strings are Anagram 

Explaination: As all the elements in str1 are exact same as to create str2 .
i.e., we can create str2 using elements of str1 without removing any element or removing any extra element.

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22. Java String Program to Reverse a String

Input: str= "Geeks"
Output: "skeeG"

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23. Java String Program to Remove leading zeros

Input : 00000123569
Output : 123569

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Java Practice Problems for Searching Algorithms

24. Write a Java Program for Linear Search.

Time Complexity: O(N)
Space Complexity: O(N)

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25. Write a Binary Search Program in Java.

Time Complexity: O(logN)
Space Complexity: O(N)

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Practice Problems in Java Sorting Algorithms

26. Java Program for Bubble Sort.

Time Complexity: O(N ² )
Space Complexity: O(1)

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27. Write a Program for Insertion Sort in Java.

Time Complexity: O(N ² )
Space Complexity: O(1)

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28. Java Program for Selection Sort.

Time Complexity: O(N ² )
Space Complexity: O(1)

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29. Java Program for Merge Sort.

Time Complexity: O(N logN)
Space Complexity: O(N)

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30. Java Program for QuickSort.

Time Complexity: O(N logN)
Space Complexity: O(1)

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Conclusion

After completing these Java exercises you are a step closer to becoming an advanced Java programmer. We hope these exercises have helped you understand Java better and you can solve beginner to advanced-level questions on Java programming.

Solving these Java programming exercise questions will not only help you master theory concepts but also grasp their practical applications, which is very useful in job interviews.

More Java Practice Exercises

• Java Array Exercise
• Java String Exercise
• Java Collection Exercise

Click Here - To Practice Java Online please check our Practice Portal.

Java Exercise - FAQ

1. How to do Java projects for beginners?

To do Java projects you need to know the fundamentals of Java programming. Then you need to select the desired Java project you want to work on. Plan and execute the code to finish the project. Some beginner-level Java projects include:

• Reversing a String
• Number Guessing Game
• Creating a Calculator
• Simple Banking Application
• Basic Android Application

2. Is Java easy for beginners?

As a programming language, Java is considered moderately easy to learn. It is unique from other languages due to its lengthy syntax. As a beginner, you can learn beginner to advanced Java in 6 to 18 months.

3. Why Java is used?

Java provides many advantages and uses, some of which are:

• Platform-independent
• Robust and secure
• Object-oriented
• Popular & in-demand
• Vast ecosystem

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Article Tags :

• Java
• Java Programs
• Output of Java Program
• Java-Library
• Java-Output
• Java-I/O
• java-basics
• Java-Object Oriented
• Java-Strings
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• Java-Data Types
• Java-Functions

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