Various ways to reverse a string in Java.

Category : Java | Sub Category : Java Programs | By Prasad Bonam Last updated: 2023-07-24 05:26:10 Viewed : 96

There are various ways to reverse a string in Java. Here are a few different methods:

1. Using a StringBuilder:

javaCopy code
import java.util.Scanner;

public class ReverseString {

    public static String reverseWithStringBuilder(String inputString) {
        StringBuilder reversedString = new StringBuilder(inputString);
        reversedString = reversedString.reverse();
        return reversedString.toString();
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a string to reverse: ");
        String userInput = scanner.nextLine();

        String reversedString = reverseWithStringBuilder(userInput);

        System.out.println("Reversed string: " + reversedString);
    }
}

2. Using a character array:

javaCopy code
import java.util.Scanner;

public class ReverseString {

    public static String reverseWithCharArray(String inputString) {
        char[] charArray = inputString.toCharArray();
        int start = 0;
        int end = inputString.length() - 1;

        while (start < end) {
            char temp = charArray[start];
            charArray[start] = charArray[end];
            charArray[end] = temp;
            start++;
            end--;
        }

        return new String(charArray);
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a string to reverse: ");
        String userInput = scanner.nextLine();

        String reversedString = reverseWithCharArray(userInput);

        System.out.println("Reversed string: " + reversedString);
    }
}

3. Using recursion:

javaCopy code
import java.util.Scanner;

public class ReverseString {

    public static String reverseWithRecursion(String inputString) {
        if (inputString.isEmpty()) {
            return inputString;
        } else {
            return reverseWithRecursion(inputString.substring(1)) + inputString.charAt(0);
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a string to reverse: ");
        String userInput = scanner.nextLine();

        String reversedString = reverseWithRecursion(userInput);

        System.out.println("Reversed string: " + reversedString);
    }
}

You can choose any of these methods to reverse a string in Java based on your preference and requirements. Each method has its own advantages and may be more suitable in different situations.