Design Patterns and Best Practices in Java

Polymorphism

In broad terms, polymorphism gives us an option to use the same interface for entities of different types. There are two major types of polymorphism, compile time and runtime. Say you have a Shape class that has two area methods. One returns the area of a circle and it accepts single integer; that is, the radius is input and it returns the area. Another method calculates the area of a rectangle and takes two inputs, length and breadth. The compiler can decide, based on the number of arguments in the call, which area method is to be called. This is the compile-time type of polymorphism.

There is a group of techies who consider only runtime polymorphism as real polymorphism. Runtime polymorphism, also sometimes known as subtyping ...