what is it's error it is not running.please found to me.

Question

#include <stdio.h>

int main()
{
    int n,rev=0,rem,temp;
    printf("Enter a number");
    scanf("%d",&n);
    temp=n;
    
    for(0<n;
    
       rem=n%10;
        rev=(rev*10)+rem;
        n=n/10; }
    
    printf("value of %d is %d",rev,temp);
    
    return 0;
}

Answer 1

Instead of the for statement for your loop you should (correctly) use the while statement:

while (0 < n)

That should get your problem sorted.

You should also consider giving more talkative variable names. Your code would look something like this after some clean-up:

#include <stdio.h>

int main()
{
    int number;
    printf("Enter a number to reverse its digits: ");
    scanf("%d", &number);
    int temp = number;
    int reverse = 0;    
    while (0 < temp)
    {
        int remainder = temp % 10;
        reverse = reverse * 10 + remainder;
        temp /= 10;
    }    
    printf("Reverse of %d is %d.\n", number, reverse);
    return 0;
}