Java Programming · Module 6 of 10

Inheritance and polymorphism

Reuse and extend classes with extends, override behaviour, and use one interface for many forms.

📖 Key ideas

class Dog extends Animal: Dog inherits Animal's fields and methods.
super calls the parent constructor or method.
@Override replaces a parent method in the child.
Polymorphism: an Animal variable can hold a Dog; the Dog version of a method runs.
Java allows single class inheritance only.

💡 Real-life example: A smartphone inherits from phone: it can still call, but it also overrides the screen with touch.

extendsInherits from a class

superRefers to the parent class

@OverrideMarks a method that replaces a parent method

PolymorphismOne reference, many forms