User-defined functions

We have already seen user-defined functions, the example we have given at the beginning of this tutorial is an example of user-defined function. The functions that we declare and write in our programs are user-defined functions. Lets see another example of user-defined functions.

#include <iostream>
#include <cmath>
using namespace std;
//Declaring the function sum
int sum(int,int);

int main(){
   int x, y;
   cout<<"enter first number: ";
   cin>> x;

   cout<<"enter second number: ";
   cin>>y;

   cout<<"Sum of these two :"<<sum(x,y);
   return 0;
}
//Defining the function sum
int sum(int a, int b) {
   int c = a+b;
   return c;
}