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This video tutorial illustrates finding factorial of a given number using C programming.

In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n.

**Ex:**

if user enters 5, then the factorial is 1 * 2 * 3 * 4 * 5 i.e., factorial = 120

This logic must be handled with a c program.

**Full Source Code**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | #include < stdio.h > #include < conio.h > void main() { int num, i, fact = 1; clrscr(); printf("Enter a number\n"); scanf("%d", &num); for( i = 1; i < = num; i++ ) fact = fact * i; // fact *= i; printf("\nFactorial of %d is %d", num, fact); getch(); } |

Here the for loop stars from 1 and not 0. As anything multiplied by 0 would also be zero.

**Note:** Factorial of 0 is 1. i.e., 0! = 1

fact *= i; is the compact representation of fact = fact * i;

**Video Tutorial: Factorial in c**

YouTube Link: http://www.youtube.com/watch?v=PYLaSrO84nU [Watch the Video In Full Screen.]

**Output:**

Enter a number

5

Factorial of 5 is 120

**Also Watch/Read:** Find the Factorial of a Number: C++