This C program calculates the the factorial of an integer number entered by the user. The function uses for loop to calculate the factorial and returns the number. Program terminates if a non integer number is entered. This C language program uses for loop in just a single statement to calculates the factorial of integer number.

/*******************************************************
* MYCPLUS Sample Code - https://www.mycplus.com *
* *
* This code is made available as a service to our *
* visitors and is provided strictly for the *
* purpose of illustration. *
* *
* Please direct all inquiries to saqib at mycplus.com *
*******************************************************/

#include <stdio.h>

int fact(int n);

int main(void) {
int current;

printf("Enter a positive integer [to terminate enter non-positive] > ");
scanf("%d", &amp;t);
while (current > 0) {
printf("The factorial of %d is %d\n", current, fact(current));
printf("Enter a positive integer [to terminate enter non-positive] > ");
scanf("%d", &amp;t);
}
}

/* n is a positive integer. The function returns its factorial */
int fact(int n) {
int lcv; /* loop control variable */
int p; /* set to the product of the first lcv positive integers */

for(p=1, lcv=2; lcv <= n; p=p*lcv, lcv++);
return p;
}