overload and override in C++

C plus plus (c++) provide overloading and overriding function :

1. Overloading
   • have the same function name
   • exit in the same class( if have class)
   • difference signature (type or number parameter)
   • allow more than definition for a function name

Example :

// www.learning2night.com
#include <iostream>


using namespace std;

	 int sum(int a,int b){
		return a+b;
	}

	 int sum(int a,int b,int c){
		return a+b+c;
	}
	float sum(float a, float b){
		return a+b;
	}

	double sum(double a, double b){
		return a+b;
	}

int main(){
    cout<<"sum int "<<sum(1,2)<<endl;
    cout<<"sum int 3 parameters "<<sum(1,2,3)<<endl;
    cout<<"sum double "<<sum(1.0D,2.0D)<<endl;
    cout<<"sum float "<<sum(1.0,2.0)<<endl;
    return 0;
}

Output:

sum int 3
sum int 3 parameters 6
sum double 3
sum float 3

2. Overriding
   • have the same function name and signature
   • exit in inheritance
   • must be done in class
   • child class override function of parent(s) class

Example:

// www.learning2night.com
#include<iostream>

using namespace std;

class Base{
public:
    void display(){
        cout<<"Parent Class "<<endl;

    }
};

class Derived: public Base{
public:
//  override function
    void display(){
        cout<<"child class "<<endl;
    }
};

int main(){
    Derived d;
    d.display();
    return 0;
}

Output:

child class