ReverseANumber.java

package com.codinginterview;

import java.util.Scanner;

public class ReverseANumber {

 public static void main(String[] args) {
 Scanner scanner = new Scanner(System.in);
 System.out.println("Enter a Number:");
 int num = scanner.nextInt();
 System.out.println( "Number is :: "+ num);
 System.out.println("Reverse Number-1 is :: "+ reverseNumber1(num));
 System.out.println("Reverse Number-2 is :: "+ reverseNumber2(num));
 System.out.println("Reverse Number-3 is :: "+ reverseNumber3(num));
 // System.out.println("Reverse Number-4 is :: "+ reverseNumber4(num));
 }
 private static int reverseNumber1(int num){
 int rev = 0;
 while(num != 0){
 rev = rev*10 + num%10;
 num = num / 10;
 }
 return rev;
 }
 private static int reverseNumber2(int num){

 StringBuffer sb = new StringBuffer(num + "" );
 return Integer.parseInt(sb.reverse().toString());
 }
 private static int reverseNumber3(int num){

 StringBuilder sb = new StringBuilder(num + "");
 return Integer.parseInt(sb.reverse().toString());
 }
}