Java Polymorphism and Inheritance

Polymorphism in Java

• Polymorphism is the ability of an object to take on multiple forms, which is implemented in Java through method overriding or method overloading.

Demonstrating Polymorphism

• The method used to demonstrate polymorphism in Java code is method overriding, where a subclass provides a specific implementation of a method that is already defined in its superclass.

Explicit Downcasting

• The purpose of explicit downcasting in Java is to convert a supertype object reference to a subtype object reference, which is necessary when the compiler cannot guarantee the subtype class.

Dynamic Binding

• Dynamic binding in Java refers to the process of determining the specific implementation of a method at runtime based on the object being used.

Subtype and Supertype Objects

• An object of a subtype can be used wherever its supertype value is required, meaning that a subtype object can be treated as its supertype.
• A variable of a supertype can refer to a subtype object, but a variable of a subtype cannot refer to a supertype object.

Additional Facts

• Polymorphism does not allow a variable of a subtype to refer to a supertype object.
• In Java, explicit downcasting is necessary when converting a supertype to a subtype.
• The equals method in the Object class is used to compare two objects based on their contents.