# Reverse of a Number using while loop in C

## Program code to find Reverse of a Number in C:

#include<stdio.h> #include<conio.h> void main() { int n,a,r,s=0; clrscr(); printf("\n Enter The Number:"); scanf("%d",&n); a=n; //LOOP FOR FINDING THE REVERSE OF A NUMBER while(n>0) { r=n%10; s=s*10+r; n=n/10; } printf("\n The Reverse Number of %d is %d",a,s); getch(); }

**Related:** Reverse of a Number using while loop in C++

## Working:

- First the computer reads a number from the user.
- Then using while loop the reverse number is calculated and stored in the variable ‘s’.
- Finally the reverse of a given number is printed.

## Step by step working of the above C program:

Let us assume a number entered is **123.**

So n=123 , s=0

- n>0 (123>0) while loop condition is true

r=n%10 (r=123%10) So r=3

s=s*10+r (s=0*10+3) So s=3

n=n/10 (n=123/10) So n=12

- n>0 (12>0) while loop condition is true

r=n%10 (r=12%10) So r=2

s=s*10+r (s=3*10+2) So s=32

n=n/10 (n=12/10) So n=1

- n>0 (1>0) while loop condition is true

r=n%10 (r=1%10) So r=1

s=s*10+r (s=32*10+1) So s=321

n=n/10 (n=1/10) So n=0

- n>0 (0>0) while loop condition is false

It comes out of the while loop and prints the reverse number which is stored in variable “s”.

- Thus the program execution is completed.

## Output:

### TO DOWNLOAD THE PROGRAM CODE :CLICK HERE