Differentiate between function overloading and function overriding

Overloading a method (or function) in C++ is the ability for functions of the same name to be defined as long as these methods have different signatures (different set of parameters). Method overriding is the ability of the inherited class rewriting the virtual method of the base class.

a) In overloading, there is a relationship between methods available in the same class whereas in overriding, there a is relationship between a superclass method and subclass method.

(b) Overloading does not block inheritance from the superclass whereas overriding blocks inheritance from the superclass.

(c) In overloading, separate methods share the same name whereas in overriding, subclass method replaces the superclass.

(d) Overloading must have different method signatures whereas overriding must have same signature.

You are putting in place an overloading when you change the original types for the arguments in the signature of a method.

You are putting in place an overriding when you change the original Implementation of a method in a derived class.

Overriding means, giving a different definition of an existing function with same parameters, and overloading means adding a different definition of an existing function with different parameters.

Example:

#include <iostream>

class base{
    public:
    //this needs to be virtual to be overridden in derived class
    virtual void show(){std::cout<<"I am base";}
    //this is overloaded function of the previous one
    void show(int x){std::cout<<"\nI am overloaded";} 
};

class derived:public base{
    public:
    //the base version of this function is being overridden
    void show(){std::cout<<"I am derived (overridden)";}
};


int main(){
    base* b;
    derived d;
    b=&d;
    b->show();  //this will call the derived overriden version
    b->show(6); // this will call the base overloaded function
}

Output:

I am derived (overridden)
I am overloaded

Function overloading is done when you want to have the same function with different parameters

void Print(string s);//Print string
void Print(int i);//Print integer

Function overriding is done to give a different meaning to the function in the base class

class Stream//A stream of bytes
{
public virtual void Read();//read bytes
}

class FileStream:Stream//derived class
{
public override void Read();//read bytes from a file
}
class NetworkStream:Stream//derived class
{
public override void Read();//read bytes from a network
}