How to Reverse a String in Java – Multiple Ways

Reverse a String in Java – 4 Simple Methods

Reversing a string is a frequently asked interview question and a great exercise for beginners learning Java. Below are four common ways to reverse a string.

1. Using for Loop

public class ReverseStringLoop {
    public static void main(String[] args) {
        String input = "SpringJavaLab";
        String reversed = "";

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

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

2. Using StringBuilder

public class ReverseStringBuilder {
    public static void main(String[] args) {
        String input = "SpringJavaLab";
        StringBuilder sb = new StringBuilder(input);
        System.out.println("Reversed: " + sb.reverse());
    }
}
  

3. Using Recursion

public class ReverseStringRecursion {
    public static String reverse(String str) {
        if (str == null || str.length() <= 1) {
            return str;
        }
        return reverse(str.substring(1)) + str.charAt(0);
    }

    public static void main(String[] args) {
        String input = "SpringJavaLab";
        System.out.println("Reversed: " + reverse(input));
    }
}
  

4. Using Java 8 Streams

import java.util.stream.Collectors;

public class ReverseStringStream {
    public static void main(String[] args) {
        String input = "SpringJavaLab";

        String reversed = new StringBuilder(input)
            .chars()
            .mapToObj(c -> (char) c)
            .collect(Collectors.collectingAndThen(
                Collectors.toList(),
                list -> {
                    java.util.Collections.reverse(list);
                    return list.stream()
                               .map(String::valueOf)
                               .collect(Collectors.joining());
                }
            ));

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

💡 Conclusion

There are multiple ways to reverse a string in Java. Choose StringBuilder for performance, recursion for learning, and streams for a functional approach. Practicing these helps improve logic and understanding of Java's core features.

You might also want to check for Palindrome Strings using the reversed string.

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