# Java Exercises – Basic to Advanced Java Practice Programs with Solutions

Last Updated : 13 Mar, 2024

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.

Take a look at our 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

### 1. Write Hello World Program in Java

The solution to the Problem is mentioned below:

Java ``` // 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!"); } } ```

Output
```Hello World!

```

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

```Input: 2 3
Output: 5
```

### 3. Write a Program to Swap Two Numbers

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

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

```Input: 9
Output: 1001
```

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

```Input: 5
Output: 120
```

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

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

### 7. Write a Program to Calculate Simple Interest in Java

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

### 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
```

### 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.
```

## Pattern Programs in Java

```    *
***
*****
*******
```

### 11. Write a Java Program to Print Pattern.

```* * * * * *
*         *
*         *
*         *
*         *
* * * * * *
```

### 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
```

### 13. Java Program to Print Patterns.

```     *
***
*****
*******
*********
***********
*********
*******
*****
***
*
```

## Array Programs in Java

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

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

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

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

### 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] ]
```

### 17. Java Array Program For Array Rotation

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

### 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 ]
```

### 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]
```

## String Programs 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
```

### 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.
```

### 22. Java String Program to Reverse a String

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

### 23. Java String Program to Remove leading zeros

```Input :Â 00000123569
Output :Â 123569
```

## Java Practice Problems for Searching Algorithms

### 24. Write a Java Program for Linear Search.

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

### 25. Write a Binary Search Program in Java.

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

## Practice Problems in Java Sorting Algorithms

### 26. Java Program for Bubble Sort.

Time Complexity: O(N2)
Space Complexity: O(1)

### 27. Write a Program for Insertion Sort in Java.

Time Complexity: O(N2)
Space Complexity: O(1)

### 28. Java Program for Selection Sort.

Time Complexity: O(N2)
Space Complexity: O(1)

### 29. Java Program for Merge Sort.

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

### 30. Java Program for QuickSort.

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

## 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.

## FAQ in Java Exercise

### 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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