C Program to reverse the digits of a given number.

C Program to reverse a given number using Recursive function.

1) Using Recursion
2) Using While loop

#include<stdio.h>

int main(){

   int num,reverse_number;

   //User would input the number

   printf("\nEnter any number:");

   scanf("%d",&num);

   //Calling user defined function to perform reverse

   reverse_number=reverse_function(num);

   printf("\nAfter reverse the no is :%d",reverse_number);

   return 0;

}

int sum=0,rem;

reverse_function(int num){

   if(num){

      rem=num%10;

      sum=sum*10+rem;

      reverse_function(num/10);

   }

   else

      return sum;

   return sum;

}

Reversing a number using the While loop

• In the above program, we learned how to reverse a number using a recursive function. Here we would learn how to do it using a while loop.

#include<stdio.h>

int main()

{

   int num,rem,reverse_num=0;

   //Input number

   printf("\nEnter any number:");

   scanf("%d",&num);

   while(num>=1)

   {

      rem = num % 10;

      reverse_num = reverse_num * 10 + rem;

      num = num / 10;

   }

   printf("\nReverse of input number is: %d", reverse_num);

   return 0;

}

Expected Output:

Enter any number: 49212

Reverse of input number is: 21294