C++ Recursion

In C++, a function can call itself. A function is said to be recursive if a statement in the body of the function calls itself.

Syntax

recursionfunction(){  
recursionfunction(); //calling self function  
}

A function that calls itself, and doesn't perform any task after function call, is known as tail recursion. In tail recursion, we generally call the same function with return statement.

Example

Let's see an example to print factorial number using recursion in C++ language.

snippet

#include<iostream>
using namespace std;  
int main()
{
int factorial(int);
int fact,value;
cout<<"Enter any number: ";
cin>>value;
fact=factorial(value);
cout<<"Factorial of a number is: "<<fact<<endl;
return 0;
}
int factorial(int n)
{
if(n<0)
return(-1); /*Wrong value*/  
if(n==0)
return(1);  /*Terminating condition*/
else
{
return(n*factorial(n-1));    
}
}

Output

Enter any number: 5 Factorial of a number is: 120

We can understand the above program of recursive method call by the figure given below: