SUB CLASS JAVA

 Develop a JAVA program to create a class named shape. Create three sub classes namely: circle, triangle and square, each class has two member functions named draw () and erase (). Demonstrate polymorphism concepts by developing suitable methods, defining member data and main program.

project-folder/

└── jones/

    ├── Shape.java

    ├── Circle.java

    ├── Triangle.java

    ├── Square.java

    └── Main.java

Note:

Java starts execution from the class that has the main()

 

FILE 1: Shape

 

package jones;

 

public class Shape {

      

              public void draw() {

              System.out.println("Drawing a shape");

              }

              public void erase() {

              System.out.println("Erasing a shape");

              }

              }

 

----------------------------------------------------------------------------------------------

FILE 2: Circle

package jones;

 

 

public class Circle extends Shape {

      

              @Override

              public void draw() {

              System.out.println("Drawing a circle");

              }

              @Override

              public void erase() {

              System.out.println("Erasing a circle");

              }

              }

----------------------------------------------------------------------------------------------

FILE 3: Triangle

 

package jones;

 

 

 

public class Triangle extends Shape {

      

              @Override

              public void draw() {

              System.out.println("Drawing a triangle");

              }

              @Override

              public void erase() {

              System.out.println("Erasing a triangle");

              }

              }

----------------------------------------------------------------------------------------------

FILE 4: Square

 

package jones;

 

 

public class Square extends Shape {

      

              @Override

              public void draw() {

              System.out.println("Drawing a square");

              }

              @Override

              public void erase() {

              System.out.println("Erasing a square");

              }

              }

----------------------------------------------------------------------------------------------

FILE 5: main (Run Through this class)

 

package jones;

 

public class Main {

      

       public static void main(String[] args)

       {

       Shape shape = new Shape();

       Circle circle = new Circle();

 

       Triangle triangle = new Triangle();

       Square square = new Square();

       shape.draw();

       shape.erase();

       circle.draw();

       circle.erase();

       triangle.draw();

       triangle.erase();

       square.draw();

       square.erase();

       }

       }

 STEP 1

STEP 2

STEP 3

STEP 4:  Execute ” Main.java”