jav 1

// Java program to illustrate the
// concept of Abstraction
abstract class Shape {
    String color;
 
    // these are abstract methods
    abstract double area();
    public abstract String toString();
 
    // abstract class can have the constructor
    public Shape(String color)
    {
        System.out.println("Shape constructor called");
        this.color = color;
    }
 
    // this is a concrete method
    public String getColor() { return color; }
}
class Circle extends Shape {
    double radius;
 
    public Circle(String color, double radius)
    {
 
        // calling Shape constructor
        super(color);
        System.out.println("Circle constructor called");
        this.radius = radius;
    }
 
    @Override double area()
    {
        return Math.PI * Math.pow(radius, 2);
    }
 
    @Override public String toString()
    {
        return "Circle color is " + super.getColor()
            + "and area is : " + area();
    }
}
class Rectangle extends Shape {
 
    double length;
    double width;
 
    public Rectangle(String color, double length,
                     double width)
    {
        // calling Shape constructor
        super(color);
        System.out.println("Rectangle constructor called");
        this.length = length;
        this.width = width;
    }
 
    @Override double area() { return length * width; }
 
    @Override public String toString()
    {
        return "Rectangle color is " + super.getColor()
            + "and area is : " + area();
    }
}
public class Test {
    public static void main(String[] args)
    {
        Shape s1 = new Circle("Red", 2.2);
        Shape s2 = new Rectangle("Yellow", 2, 4);
 
        System.out.println(s1.toString());
        System.out.println(s2.toString());
    }
}