What is polymorphism in Object Oriented Programming (OOPS) Languages?
In object-oriented programming, polymorphism is a generic term that means 'many shapes'. (from the Greek meaning "having multiple forms").
Polymorphism is briefly described as "one interface, many implementations." polymorphism is a characteristic of being able to assign a different meaning or usage to something in different contexts - specifically, to allow an entity such as a variable, a function, or an object to have more than one form.
There are two types of polymorphism one is compile time polymorphism and the other is run time polymorphism. Compile time polymorphism is functions and operators overloading. Runtime time polymorphism is done using inheritance and virtual functions. Here are some ways how we implement polymorphism in Object Oriented programming languages
Interface and abstract methods
Like in C# or JAVA different classes implement a common interface in different ways; is an example of Runtime polymorphism. The interface defines the abstract member functions (no implementation). In class that implement the interface; we define body of those abstract members according to the requirement. Means single definition in interface but multiple implementation in child classes.
Virtual member functions
Using virtual member functions in an inheritance hierarchy allows run-time selection of the appropriate member function. A virtual function is a member function of the base class and which is redefined by the derived class. Such functions can have different implementations that are invoked by a run-time determination of the subtype (virtual method invocation, dynamic binding).
Function Overloading
Polymorphism means that functions assume different forms at different times. In case of compile time it is called function overloading.Two or more functions can have same name but their parameter list should be different either in terms of parameters or their data types. The functions which differ only in their return types cannot be overloaded. The compiler will select the right function depending on the type of parameters passed.
Operator Overloading
In polymorphism operators can also be overloaded (Compile time polymorphism). Operators can be overloaded in order to perform special functions with respect to the class. With the help of operator overloading standard operations such as + , - , * , etc can be applied on the objects of the class.