Thread: Reverse number programming

I am having difficulty to understand following program.

Code:

#include<stdio.h>
int main (void)
{
    unsigned int number;
    int reverse=0; 
    printf("Enter number to reverse \n");
    scanf("%d", &number);  
  
 while (number != 0)
 {
  reverse = reverse * 10;
  reverse = reverse + number % 10;
  number   = number / 10;
 }
 printf("Reverse number is = %d \n", reverse);
  
 return 0;
}

I don't understand this part of program

Code:

while (number != 0)
 {
  reverse = reverse * 10;
  reverse = reverse + number % 10;
  number   = number / 10;
 }

let's say I want to get reverse number of 835 then
5*100 =500
3*10 = 30
8*1 = 8
------------------
= 538

835 -- reverse number - 538

Originally Posted by Salem

Either

Use a debugger to single step the code and observe how each variable changes with each statement.

Or add three more printf calls inside the loop to show you what each variable contains.

Thanks Now I understood
Enter number to reverse
123
Reverse number 0
Reverse number is = 3
number is = 12
Reverse number is = 3
Reverse number 30
Reverse number is = 32
number is = 1
Reverse number is = 32
Reverse number 320
Reverse number is = 321
number is = 0
Reverse number is = 321