Inheritance in Java

The use of "this " keyword in Java

Inheritance in Java is a mechanism that is used to pass properties and behaviours of a parent object to child objects.

In inheritance, you can create new classes that are built using existing classes.Inheritance represents IS_A relationship i.e parent-child relationship.
A child class can use methods and fields of the parent class.

Importance of Inheritance in Java

1.For method overriding .

2.Code reuse.

Inheritance Syntax

extends keyword is used to make a child class from the parent.

public class JButtonListener  extends JFrame {
}

Java Inheritance Example

Parent Class

public class Students {
    int id;
    String name;
    String class_name;
    String school_name="Ikuu Boys";
    
    
}

Child Class

public class FormOneStudents extends Students {
    String  form_name="Form one West";
    public static void main(String args[])
    {
    FormOneStudents f=new FormOneStudents();
    System.out.println("School name " +f.school_name);
     System.out.println("Form name " +f.form_name);
    }
    
}

Types of Inheritance in Java

There are 3 types of inheritance in java 

• Single 
• Multilevel 
•  hierarchical.

• 1.Example of a single Inheritance java example.

public class Animal {
   
    void eat()
    {
        System.out.println("All Animals eat");
    }
    
   
}

Child Class

public class Cat extends Animal
        {
 void Meow()
 {
 System.out.println("Cats meows");
 }
 


    public static void main(String args[])
    {
   Cat c= new Cat();
   c.Meow();
   c.eat();
    
    }}

• 2.Multilevel Java Example

public class Animal {
   
    void eat()
    {
        System.out.println("All Animals eat");
    }
    
   
}



public class Cat extends Animal
        {
 void Meow()
 {
 System.out.println("Cats meows");
 }
 }
 
public class BabyCat  extends Cat{
    
  public static void main(String args[])
    {
   BabyCat c= new BabyCat();
   c.Meow();
   c.eat();
    
    }
}

• 3.Hierarchical 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  
}}