Reverse a String in Java — Definition, Examples and Program

Reverse a String in Java — Definition, Examples and Program

Reversing a string is one of the most fundamental problems in programming. It helps beginners understand loops, character handling, and string manipulation.

In this blog, we will learn:

• What it means to reverse a string
• Step-by-step examples
• A clean Java program
• Practice challenges

What Does Reversing a String Mean?

Reversing a string means changing the order of its characters so that the last character becomes the first, the second last becomes the second, and so on.

Example:

• "hello" → "olleh"
• "Java" → "avaJ"
• "12345" → "54321"

How the Logic Works

To reverse a string manually:

1. Start from the last character of the string.
2. Move towards the first character.
3. Print or store each character one by one.

Example 1

Input: "CODE"

• Start from index 3 → 'E'
• Index 2 → 'D'
• Index 1 → 'O'
• Index 0 → 'C'

Output: "EDOC"

Java Program to Reverse a String

import java.util.Scanner;

public class ReverseString {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.print("Enter a string: ");
        String input = sc.nextLine();

        String reversed = "";

        for (int i = input.length() - 1; i >= 0; i--) {
            reversed = reversed + input.charAt(i);
        }

        System.out.println("Reversed String: " + reversed);
    }
}

Sample Output

Enter a string: programming
Reversed String: gnimmargorp

Practice Challenges

1. Reverse a string without using an extra variable.
2. Reverse each word in a sentence separately.
3. Check whether a string is a palindrome using the reverse logic.

Reversing a string is a common interview question and a great way to build confidence in string manipulation. Mastering this logic will help you solve many advanced problems easily.