Showing posts with label add number. Show all posts
Showing posts with label add number. Show all posts

Thursday, 30 May 2013

How to reverse number and add using php

Many time interviewer asked me to write a program to reverse a number and add. So i am sharing this program with you.

Steps to reverse a number and add:

  • Take modulas(%) of number by 10. 
  • Add this number until condition matches. 
  • Now divide number by 10. 
  • Repeat these steps until condition matches.

That's it you got the number reversed and added.

<?php
             echo 'How to reverse number and add using php ';
             echo '<br>';
             echo $numberToReverse = 123456789;
             echo '<br>';
             if($numberToReverse > 0){
                    $sum = 0;
                    while($numberToReverse){
                           echo $numberToReverse%10;
                           $sum += $numberToReverse%10;
                           $numberToReverse = (int)($numberToReverse/10);
                     }
                     echo '<br>';
                     echo 'Sum of number : '.$sum;
              }else{
                     echo 'number should be grater then zero.';
              }
?>

Output is:
How to reverse number and add using php

123456789 // actual number

987654321 // reversed number

Sum of number : 45