Functions

There are three very important terminology related to functions while coding: -

1. Function Declaration

2. Function Definition

3. Function Call

Function Declaration: - This is also known as Function Initialization. We mostly declare a function after declaring all the header files. As soon as we declare the function, the compiler creates its lexical definition, and accordingly segmentation of memory takes place. Thus the moment compiler see the function declaration, it knows how to execute its definition on function call. In Turbo C++ you must have to declare a function whereas in Dev C++ this is not require as Dev C++ compiler takes care of this.

Function Definition: - A function contains definition about the supposed task we have to perform. When a function have parameters passed to it, then it is parametric function. When a function does not contains any parameters then it is non-parametric function.

Function Call: - The function call can take place within a class, a function and main() function. When a function call itself in its body, then such a function is known as recursive function.

Addition of two numbers using parametric function in C++ (Dev C++ Editor)

/*Program 1

Date : 20 - March - 2019

Program name : Addition of two numbers using functions

Developer : Aditi B*/

#include <iostream>

using namespace std;

int add(int,int); //function declaration

int add (int x, int y)

{

// defining the function

int z;

z = x+y; //add the parameter objects and assign it to variable z.

return z; // function always return a value.

}

int main()

{

int a, b, sum;

cout << "Enter Number 1: \t";

cin >> a;

cout << "Enter Number 2: \t";

cin >> b;

sum = add(a,b); // Initialising the function and passing parameters

cout <<"\n---------------------------------------------------------";

cout << "\n the addition of given two numbers is:\t" << sum;

cout <<"\n---------------------------------------------------------\n\n\n";

return 0;

}