Inheritance in Java

·       Inheritance is very important concept in java

• Java allows you to extends a class  with another class

•  Is use for sharing between two classes (from parent class to child  class)    
• extends keyword provide inheritance in java

Example for your understanding 

class A         // its our base class or parent class

{

int a=12;   //initialization the value of variable a=2

}

class B extends A    // its our derived class or child class

{

void display()       // declaration of method display

{

System.out.println(+a);    // for print value of a which initialize in claas A

}

}

class demo // main class

{

public static void main(String [] args)   // main method

{

B obj=new B();    //create object for class B

obj.display();    //accessing method display

}

} 

Firstly remember that

// after this line you can give comment

Anything you written after // is your comment

For that hole line only

Explanation of the above program

Here we take three classes

class A

class B

and class demo its our main class

class A is our parent class

and

class B extends A

means

all properties of patent class A is extended

by the child class B

we declare method display in class B

System.out.println(+a);

Here we want to print the value of

'a'

but value is initialize in class A

we know that by extend keyword

we can access all properties of class A

and we given value of a=12 in class A

hence in above program we get output

12