Reverse a Number
This program reverses a number using while loop.
Problem Statement
Write a Java program that reverses the number 1234 using while loop.
Source Code
| 1 | public class ReverseNumber { |
| 2 | public static void main(String[] args) { |
| 3 | int num = 1234, rev = 0; |
| 4 | while(num > 0) { |
| 5 | rev = rev * 10 + num % 10; |
| 6 | num /= 10; |
| 7 | } |
| 8 | System.out.println("Reversed number = " + rev + " - Eduinq"); |
| 9 | } |
| 10 | } |
Program Output
Reversed number = 4321 - Eduinq
Explanation
The program extracts digits using num % 10 and appends them to rev by multiplying rev by 10. Then it removes the last digit using num /= 10. The loop continues until num becomes 0. This demonstrates how while loops can reverse numbers digit by digit. Shows how while loop can reverse a number.