TODAY JAVA SCHOOL

Types of inheritance in java

There are  three types of inheritance in java: single, multilevel and hierarchical.

1.    Single Inheritance

In single inheritance, subclasses inherit the features of one superclass. In image below, the class A serves as a base class for the derived class B.

single inheritance

Example:

    class Animal{  

    void eat(){System.out.println("eating...");}  

}  

    class Dog extends Animal{  

    void bark(){System.out.println("barking...");}  

}  

    class TestInheritance{  

    public static void main(String args[]){  

    Dog d=new Dog();  

   d.bark();  

   d.eat();  

}}  

Output:

Barking…..

Eating……

1.    Multilevel Inheritance

In Multilevel Inheritance, a derived class will be inheriting a base class and as well as the derived class also act as the base class to other class. In below image, the class A serves as a base class for the derived class B, which in turn serves as a base class for the derived class C. In Java, a class cannot directly access the grandparent’s members.

multilevel inheritance

Example:

    class Animal{  

    void eat(){System.out.println("eating...");}  

}  

    class Dog extends Animal{  

    void bark(){System.out.println("barking...");}  

}  

   class BabyDog extends Dog{  

   void weep(){System.out.println("weeping...");}  

}  

   class TestInheritance2{  

   public static void main(String args[]){  

    BabyDog d=new BabyDog();  

   d.weep();  

   d.bark();  

   d.eat();  

}  }               

    Output:

Weeping…..

Eating…..

Braking…..

1.    Hierarchical Inheritance

In Hierarchical Inheritance, one class serves as a superclass (base class) for more than one sub class.In below image, the class A serves as a base class for the derived class B,C and D.

herarchical inheritance

Example:

     class Animal{  

     void eat(){System.out.println("eating...");}  

}  

     class Dog extends Animal{  

     void bark(){System.out.println("barking...");}  

}  

     class Cat extends Animal{  

     void meow(){System.out.println("meowing...");}  

}  

     class TestInheritance3{  

     public static void main(String args[]){  

     Cat c=new Cat();  

     c.meow();  

    c.eat();  

    //c.bark();//C.T.Error  

} } 

   

   Output:

     Meowing……

Eating……….