Factorial of a Number in C using For Loop
Before going to the program first let us understand what is a Factorial of a Number?
Factorial of a Number:
The factorial of a Number n, denoted by n! , is the product of all positive integers less than or equal to n.
The value of 0! is 1 according to the convention for an empty product.
For example,
4! = 4 * 3 * 2 * 1 = 24
Program code for Factorial of a Number in C:
#include<stdio.h> #include<conio.h> void main() { int n,i,f=1; clrscr(); printf("\n Enter The Number:"); scanf("%d",&n); //LOOP TO CALCULATE FACTORIAL OF A NUMBER for(i=1;i<=n;i++) { f=f*i; } printf("\n The Factorial of %d is %d",n,f); getch(); }
Related: Factorial of a Number in C++ using For Loop
Working:
- First the computer reads the number to find the factorial of the number from the user.
- Then using for loop the value of ‘i’ is multiplied with the value of ‘f’.
- The loop continues till the value of ‘n’.
- Finally the factorial value of the given number is printed.
Step by Step working of the above Program Code:
Let us assume that the number entered by the user is 4.
- It assigns the value of n=4 , i=1 , f=1
- Then the loop continues till the condition of the for loop is true.
2.1. i<=n (1<=4) , for loop condition is true.
f=f*i (f=1*1) So f=1
i++ (i=i+1) So i=2
2.2. i<=n (2<=4) , for loop condition is true.
f=f*i (f=1*2) So f=2
i++ (i=i+1) So i=3
2.3. i<=n (3<=4) , for loop condition is true.
f=f*i (f=2*3) So f=6
i++ (i=i+1) So i=4
2.4. i<=n (4<=4) , for loop condition is true.
f=f*i (f=6*4) So f=24
i++ (i=i+1) So i=5
2.5. i<=n (5<=4) , for loop condition is true.
It comes out of the for loop.
- Finally it prints as given below
The Factorial of 4 is 24
- Thus the program execution is completed.
Output:
TO DOWNLOAD THE PROGRAM CODE :CLICK HERE