all_oops.java

class One {

    public void display() {

        System.out.println("One");

    }

}

//inheritance

class Two extends One {

    @Override

    public void display() {

        System.out.println("Two");

    }

    public int add(int x, int y) {

        return x+y;

    }

//Overload

    public double add(double x,double y) {

        return x+y;

    }

}

//encapsulation example

class EncapTest {

    private String name;

    public String getName() {

        return name;

    }

    public void setName(String newName) {

        name = newName;

    }

}

//abstraction

abstract class TwoWheeler {

    public abstract void run();

}

class Honda extends TwoWheeler{

    public void run(){

        System.out.println("\nbike is Running..");

    }

}

class all_oops {

    public static void main(String[] args) {

        One a=new One();

        a.display();

        Two b=new Two();

        b.display();

        System.out.println(b.add(4,2));

        System.out.println(b.add(5.,2.)); //polymorphism

        EncapTest encap = new EncapTest();

        encap.setName("Sandeep's");

        System.out.print("Name : " + encap.getName() );

        TwoWheeler test = new Honda();

        test.run();

    }

}