How to reverse a string without using the reverse() method in java?

In this section, you will see how to reverse a string without using the predefined method reverse(). Here we have explained the two solutions for the string reverse using recursion and without using recursion.

Let’s see both solutions below:

Solution #1 : Using Recursion

ReverseStringWithRecursion.java

package com.javacodepoint.programs;

import java.util.Scanner;

public class ReverseStringWithRecursion {

        //Main method
	public static void main(String[] args) {

		// String variable to take a string input from the user
		String str = null;

		// Creating scanner class object for reading user input
		Scanner sc = new Scanner(System.in);

		System.out.println("Please enter a string to reverse: ");

		// reading the string input
		str = sc.next();
		
		//Final output
		System.out.println("Reverse of the given string is "+reverseString(str));

	}

	// Recursive method
	public static String reverseString(String str) {

		// return empty when string is empty
		if (str.equals("")) {
			return str;
		}

		return reverseString(str.substring(1)) + str.charAt(0);
	}

}

OUTPUT:

Please enter a string to reverse:
javacodepoint
Reverse of the given string is tniopedocavaj

Solution #2 : Without Using Recursion

ReverseString.java

package com.javacodepoint.programs;

import java.util.Scanner;

public class ReverseString {

	//Main method
	public static void main(String[] args) {
		
		//String variable to take a string input from the user
		String str=null;
		
		//Initializing string variable to hold the reverse of the string
		String reverse="";
		
		//Creating scanner class object for reading user input		
		Scanner sc = new Scanner(System.in);
		
		System.out.println("Please enter a string to reverse: ");
		
		//reading the string input
		str=sc.next();
		
		//iterating the string from the last to beginning
		for(int i=str.length()-1; i>=0; i--) {
			
			//picking one by one character and concatenating it with reverse
			reverse =  reverse + str.charAt(i);
		}
		
		//Final output
		System.out.println("The reverse of "+str+" is "+reverse);

	}

}

OUTPUT:

Please enter a string to reverse:
example
The reverse of example is elpmaxe


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