3! = 321 = 6
Example
Here, 5! is pronounced as "5 factorial", it is also called "5 bang" or "5 shriek".
The factorial is normally used in Combinations and Permutations (mathematics).
There are many ways to write the factorial program in c language. Let's see the 2 ways to write the factorial program.
- Factorial Program using loop
- Factorial Program using recursion
## Factorial Program using loop
Let's see the factorial Program using loop.
### Example
include<stdio.h>
int main
{
int i,fact=1,number;
printf("Enter a number: ");
scanf("%d",&number);
for(i=1;i<=number;i++){
fact=fact*i;
}
printf("Factorial of %d is: %d",number,fact);
return 0;
}
Example
Output:
Enter a number: 5
Factorial of 5 is: 120
Example
## Factorial Program using recursion in C
Let's see the factorial program in c using recursion.
### Example
include<stdio.h>
long factorial(int n)
{
if (n == 0)
return 1;
else
return(n * factorial(n-1));
}
void main
{
int number;
long fact;
printf("Enter a number: ");
scanf("%d", &number);
fact = factorial(number);
printf("Factorial of %d is %ld\n", number, fact);
return 0;
}
Example
Output:
Enter a number: 6
Factorial of 5 is: 720
Example
