Java FAQ: Top Questions

Inheritance is an object-oriented programming (OOP) mechanism in Java that allows a class (subclass or derived class) to inherit fields and methods from another class (superclass or base class). It promotes code reusability and establishes a hierarchical relationship between classes.

Key points about inheritance:

• Extends Keyword: A subclass uses the extends keyword to inherit from a superclass.
• Single Inheritance: Java supports single inheritance, meaning a class can extend only one superclass (unlike multiple inheritance in C++).
• Access to Members: Subclasses inherit non-private members (fields, methods) of the superclass, subject to access modifiers ( protected , public ).
• Super Keyword: Used to call the superclass’s constructor or methods.
• Object Class: All Java classes implicitly extend java.lang.Object , the root of the class hierarchy.