What is the difference between overloading and overriding and polymorphism in terms of C plus plus?

Answer 1

In C++, overloading, overriding, and polymorphism have the following meanings...

Overloading is when you create two functions of the same name, but with different argument types, or with a different number of arguments. The compiler generates code for each case. This can be done inside or outside a class. Operators can also be overloaded, as they are (for all practical purposes) functions, but operators can only be overloaded in the context of a class.

Overriding is when you derive a child class from a base class, and you replace a method (function) of the base class with a method of the child class using the same type and number of arguments. This is not overloading - it is redeclaration - and the overridden method only applies when dealing with an instance of the child class.

Polymorphism is the same as overriding, except that you declare any base method virtual, making all base and derived methods virtual. Virtual, in the context of a class, means to create a table in the static portion (all instances) of the class that point to the specific overridden variants of the methods of the class. This allows you to declare a pointer to the base class, initialize it with the address of an instance of either the base class or any of the child classes, invoke a method of the class, and have the proper binding determined at run-time.

Answer 2

Ploymorphism: It is the Object Oriented concept in which a single Object or function or variable is used in different forms.

Overloading: polymorphism in which the same function name is used for different implementations with different parameter list or different types of parameters.

Eg: To find the sum of integers, floats, double

int sum(int, int);

float sum(float, float);

double sum(float, float);

Note: if the retrun type is different the function is not overloaded but its a compilation error.

Overriding: if a base class function is given a definitation in the derived class then this is called function overriding.

Eg: class Base

{

int print()

{

System.out.println("Hello");

}

}

class Derived extends Base

{

int print() // overrides the function print in base class

{

System.out.println("Hi");

}

}

Note: in function overriding the drived class function's return type and the parameters should be the same as the base class function.