Polymorphism in java.

The word “poly” means many and “morphs” means forms, So it means many forms.

In Java polymorphism is mainly divided into two types:

1.Compile time Polymorphism

2.Runtime Polymorphism

1.Compile time polymorphism:  It is also known as static polymorphism. This type of polymorphism is achieved by function overloading or operator overloading. 

• Method Overloading: When there are multiple functions with same name but different parameters then these functions are said to be overloaded. Functions can be overloaded by change in number of arguments or/and change in type of arguments.
• Operator Overloading: Java also provide option to overload operators. For example, we can make the operator (‘+’) for string class to concatenate two strings. We know that this is the addition operator whose task is to add two operands. So a single operator ‘+’ when placed between integer operands, adds them and when placed between string operands, concatenates them.

In java, Only “+” operator can be overloaded:

To add integers

To concatenate strings

2.Runtime polymorphism: It is also known as Dynamic Method Dispatch. It is a process in which a function call to the overridden method is resolved at Runtime. This type of polymorphism is achieved by Method Overriding.

Method overriding, on the other hand, occurs when a derived class has a definition for one of the member functions of the base class. That base function is said to be overridden.