program to get factorial value of a number using function

using codeblocks
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//program to get factorial value of a number using function
#include<stdio.h>                      //header file
void factorial();                          // function prototype/declaration with return type zero.
int main()                              //main function
{
factorial();                                     // function calling.
return 0;                                       //returns 0 value
}
void factorial()                              // function body line ; also called function definition
{
int factorial_value=1,i;                             //initialization to value 1
 int n;                                       // variable declaration
 printf("enter a number\n");
 scanf("%d",&n);                            //input
for(i=1;i<=n;i++)                     //loop running from 1 to 100 with increment 1 each time
{
    factorial_value=factorial_value*i;                //formulation for factorial
}
printf("factorial=%d\n",factorial_value);      //output
}
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using turboc++
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//program to get factorial value of a number using function
#include<stdio.h>                      //header file
#include<conio.h>
void factorial();                          // function prototype/declaration with return type zero.
void main()                              //main function
{
factorial();                         // function calling.
getch ();                                       //holds the output
}
void factorial()                              // function body line ; also called function definition
{
int factorial_value=1,i;                             //initialization to value 1
 int n;                                       // variable declaration
 printf("enter a number\n");
 scanf("%d",&n);                            //input
for(i=1;i<=n;i++)                     //loop running from 1 to 100 with increment 1 each time
{
    factorial_value=factorial_value*i;                //formulation for factorial
}
printf("factorial=%d\n",factorial_value);      //output
}
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/* here we have used top down approach. i.e calling from top and writing its body line down.
 we can also reverse the process.*/