Java Inheritance

Source: Dev.to

What is Inheritance?

Inheritance is a mechanism where one class gets the states and behaviors of another class.
It represents an is‑a relationship, meaning inheritance should be used only when such a relationship exists between two classes.

A child class (subclass) uses features of a parent class (superclass).
The extends keyword is used to perform inheritance in Java.

Superclass

public class Employee {
    int employeeID;
    int salary;

    public static void main(String[] args) {
        // entry point
    }

    public void work() {
        System.out.println("Employee work");
    }
}

Subclass

public class Developer extends Employee {

    public static void main(String[] args) {
        Developer d1 = new Developer();

        d1.employeeID = 18426;
        d1.salary = 400000;
        System.out.println(d1.employeeID);
        System.out.println(d1.salary);
        d1.work();
        d1.devWork();
    }

    public void devWork() {
        System.out.println("Coding");
    }
}

Benefits of Inheritance

• Code reuse
• Avoid duplication
• Easier maintenance
• Builds relationships between classes

Types of Inheritance

• Single Inheritance
• Multilevel Inheritance
• Hierarchical Inheritance
• Multiple Inheritance
• Hybrid Inheritance