Java Program to Reverse a String

Java Program to Reverse a String using for loop

This java program accepts the string entered by user and reverses the string using for loop and prints the reversed string.

length method is used to get the number of characters in the string.

charAt method is used to get the character of the specified index in the string.

import java.util.*; 

public class ReverseString
{ 
   public static void main(String args[]) { 
 	Scanner sc=new Scanner(System.in);
 	System.out.println("Reverse String"); 
 	System.out.println("-----------------"); 
 	System.out.println("Enter String: "); 
 	String str = sc.nextLine();
 	String reverse = "";
 	for(int i=str.length()-1;i>=0;i--){
 		reverse = reverse + str.charAt(i);
 	}
 	System.out.println("Reverse String: "+reverse);
   } 
} 

D:\Java_Programs>javac ReverseString.java
D:\Java_Programs>java ReverseString
Reverse String
-----------------
Enter String: 
testing program
Reverse String: margorp gnitset

Java Program to Reverse a String using while loop

import java.util.*; 

public class ReverseString
{ 
   public static void main(String args[]) { 
 	Scanner sc=new Scanner(System.in);
 	System.out.println("Reverse String"); 
 	System.out.println("-----------------"); 
 	System.out.println("Enter String: "); 
 	String str = sc.nextLine();
 	String reverse = "";
 	int i=str.length()-1;
 	while(i>=0){
 		reverse = reverse + str.charAt(i);
 		i--;
 	}
 	System.out.println("Reverse String: "+reverse);

   } 
} 

D:\Java_Programs>javac ReverseString.java
D:\Java_Programs>java ReverseString
Reverse String
-----------------
Enter String: 
codingpointer!
Reverse String: !retniopgnidoc

Java Program to Reverse a String using recursion

import java.util.*; 

public class ReverseString
{ 
	public static String reverse(String original, String rev, int index){
		if(index>=0) {
			return original.charAt(index)+reverse(original, rev, index-1);
		}
		return "";
	}
   public static void main(String args[]) { 
 	Scanner sc=new Scanner(System.in);
 	System.out.println("Reverse String"); 
 	System.out.println("-----------------"); 
 	System.out.println("Enter String: "); 
 	String str = sc.nextLine();
 	String rev = "";
 	int i=str.length()-1;
 	rev = reverse(str, rev, i);
 	System.out.println("Reverse String: "+rev);

   } 
} 

D:\Java_Programs>javac ReverseString.java
D:\Java_Programs>java ReverseString
Reverse String
-----------------
Enter String: 
codingpointer!
Reverse String: !retniopgnido