C++ program to find factorial using recursion

Write a program to find the Factorial using recursive function. User will enter a number and program should display result.

Concept  used:

• Recursive function (returns number) int function(int n);
• if-else statement    
• Static variable

How program works

• User enters a number which stores in variable 'num'
• Then number passes as argument in function call
•  A static variable is used to check that how many times function is called
• When base case becomes true if(statement) then function returns result to main

c++ code

#include<iostream> using namespace std; int recursive_function(int n){     static int i=1;// to make one time initialization     cout<<i<<" : time"<<endl; // counting the function calls     if(n==1){       return 1;//base case        }    else{         i++;         return  n=n*recursive_function(n-1);         } } int main(){     cout<<"Enter to number to find Factorial: ";     int num;     cin>>num;     num=recursive_function(num); // function call     cout<<"\n\n\n\t\t\tFactorial of number is: "<<num;     cout<<"\n\n\n\n\n"; return 0; }

As a beginner some questions can be raised regarding code.
Why static variable is used instead of a simple int variable?

• The property of static variable is that it is initialized when program runs first time
• Its value increments on every call and it is not initializing again and again
• if we do not use static keyword then variable ' int i=1;' will be initialize again and again and its value will not be correct at the end infact it will remain 1 always. 
• So that is why static in has been used to count the number of calls

To provide more readable view here is image view of code:

Sample Input Output

Recommended:
To learn fast change the code and examine output.