Reverse a String Program in Java

Java Program to Reverse a String

Here we discuss about how to reverse a string without using any library function. Also we discuss about how to reverse a string using reverse method of StringBuilder.

Input String : College
Reversed String : egelloC

Reverse a String without Using any Library Function

import java.util.Scanner;
 
 public class ReverseString 
 {
 public static void main(String args[])
 {
  String str, reverse = "";
   int i, length;
   Scanner scanner = new Scanner(System.in);
 
   System.out.println("Enter any String:");
   str = scanner.nextLine();
   length = str.length();
 
   // Reversing a string
     for (i = length - 1; i >= 0; i--)
	 {
      reverse = reverse + str.charAt(i);
     }
 
     System.out.println("After Reversed String: " + reverse);
 }
}

Enter any String: College
After Reversed String: egelloC

Java Program to Reverse a String using String Builder

In this java program, we will create an object of class StringBuilder and initialize it with input string. Then we call reverse method of StringBuilder class to print reversed string on screen.

import java.util.Scanner;
 
  public class ReverseStringBuilder 
 {
  public static void main(String args[]) 
 {
  String str;
  Scanner scanner = new Scanner(System.in);
 
  System.out.println("Enter any String");
  str = scanner.nextLine();
 
  // Reversing a string
  StringBuilder str2 = new StringBuilder(str);
 
  System.out.println("After Reversed String is: " + str2.reverse());
 }
}

Enter any String: Hitesh
After Reversed String is: hsetiH