What is the best way to reverse a string in Java?

In this tutorial we will see which is the best approach to reverse a string in java.

package com.java.programs;

// Write a Java Program to reverse a string.
public class Reverse_A_String {

    public static void main(String[] args) {

        // 1st approach
        Long startTime1 = System.currentTimeMillis();
        String input1 = "Gain java knowledge";
        String output1 = "";

        for(int i = input1.length()-1; i >= 0 ;i--){
            output1 = output1+input1.charAt(i);
        }
        System.out.println("input1 : " +input1);
        System.out.println("output1 :"+ output1);
        System.out.println("Time taken by Iteration :"+ (System.currentTimeMillis()-startTime1));

        // 2nd approach
        Long startTime2 = System.currentTimeMillis();

        String input2 = "Gain java knowledge";
        StringBuilder output2 = new StringBuilder(input2);
        output2.reverse();
        System.out.println("input2 : " +input2);
        System.out.println("output2 :"+ output2);
        System.out.println("Time taken by Inbuilt function :"+ (System.currentTimeMillis()-startTime2));
    }
}

Here you can see the code above written for to reverse a string in java. I have defined to approaches and also calculated the time taken by both approaches.

2nd Approach is better . we can check the time comparison after running this code.

I/O

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