Answer to Question #185800 in C++ for bilal

Question

Let’s assume we have a class ‘Arithmetic’ with two member functions Add() and Subtract(). Suppose Add() function is defined within class then how will the subtract() function be defined out of the class boundary. Explain it with the help of some suitable program. 

Answer 1

Defining a function outside class

To define a function outside the class, it must be declared inside the class and then defined outside the class.

Syntax for function definition

return_type function_name(args);

Syntax for function definition

return_type class_name :: function_name (args)
 {
    // function definitions
 }

Example

#include <iostream>


using namespace std;
class Arithmetic {        // The class
  public:              // Access specifier
    int x=10;
    int y=6;
    
    //define the function add inside the class
    void Add(){
        cout<<x+y<<endl;
    }
    void Subtract();   //function declaration
};


// function definition outside the class
void Arithmetic::Subtract() {
  cout<<x-y;
  
}


int main() {
  Arithmetic a;     // Create an object of Arithmetic
  a.Subtract();  // Call the method Subtract
  a.Add();  //call the method Add
  return 0;
}