Recursion

Recursive function is a function that calls itself. When a function calls another function and that second function calls the third function then this kind of a function is called nesting of functions.But a recursive is the function that calls itself repeatedly.

A simple example :
main ( )
{
printf (" this is an example of recursive function");
main( );
}
 when this program is executed.The line is printed repeatedly and indefinitely.We might have to abruptly terminate the execution.

/*Program to calculate Factorial of a number */
#include <stdio.h>
void calc_factorial (int);  //function prototype
void calc_factorial (int i)
{
int I, factorial_number = 1;
for (i = 1; I < = n; ++i)
   factorial_number *=I;
printf("The factorial of %d is %d\n", n, factorial_number);
}
int main(void)
{
int number = 0;
printf(" Enter a number\n");
scanf("%d",&number);
calc_factorial (number);
return 0;
}

Sample Program Output
  Enter a number
     3
   The factorial of 3 is 6