Java Inheritance

• Inheritance in Java is a process in which sub class inherits all the properties of super class(parent class).
• In Java, inheritance is an IS-A relationship (parent-child relationship).
• In Java, inheritance is an IS-A relationship (parent-child relationship).In Java, inheritance is used for Method Overriding ( Runtime Polymorphism).
• In Java, a sub class inherits is parent or superclass by using keyword “extends”.

Types of Inheritance in Java

1) Single
2) Multilevel
3) Hierarchical
4) Multiple(Multiple inheritance is not supported in Java through class)
5) Hybrid

Single Inheritance

public class Animal {
    public void eat() {
        System.out.println("Animal Eats Food");

    }
}

public class Cat extends Animal{ // Single Inheritance
     public void speak() {
         System.out.println("Cat Says Meow");
     }
 }

Above example is called “Single Inheritance”, while below code represents “Multilevel Inheritance”.

public class BabyCat extends Cat{ // Multilevel Inheritance
    public void sleep() {
        System.out.println("Baby Cat is Sleeping");
    }
}

Above Cat extends Animal represents Single Inheritance, while BabyCat extends Cat represents Multilevel Inheritance

public  class  InheritanceExample  extends  BabyCat{
    // Example of Method Overriding
    public void eat() {
        System.out.println("Cat drinks Milk");
    }

    public static void main(String args[]) {

        // Inheritance 
        BabyCat bCat = new BabyCat(); 
        bCat.eat();
        bCat.speak();
        bCat.sleep();

        // Inheritance And Method Overriding
        InheritanceExample in_example = new InheritanceExample(); 
        in_example.eat(); // Method Overriding
    }
}

Output:

 Animal Eats Food
 Cat Says Meow
 Baby Cat is Sleeping
 Cat drinks Milk