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OOP

Implement Inheritance Heirarchy

Implement a Shape abstract class which will form the base of an inheritance hierarchy that models 2D geometric shapes. It will have:

* A non-mutable 'name' property or data member set by derived or descendant classes at construction time
* A 'area' method intended to be overridden by derived or descendant classes ( double precision floating point return value)
* A 'print' method (also for overriding) will display the shape's name, area, and all shape-specific values

Two derived or descendant classes will be created:
* Circle    -> Constructor requires a '
radius' argument, and a 'circumference' method to be implemented  
* Rectangle -> Constructor requires '
length' and 'breadth' arguments, and a 'perimeter' method to be implemented 

Instantiate an object of each class, and invoke each objects '
print' method to show relevant details.
ExpandDiskEdit
java 1.5 or above
/*
* Will work with version 1.4 if you remove the @Override annotation
* and declare floating point numbers using the primitive "double"
*/
abstract class Shape {
protected final String name;
public Shape(String name) {
this.name = name;
}
public abstract Double area();
public abstract void print();
}
class Circle extends Shape {
private Double radius;
public Circle(Double radius) {
super("circle");
this.radius = radius;
}
@Override
public Double area() {
return Math.PI * Math.pow(radius, 2);
}
@Override
public void print() {
System.out.println("A " + name + " with radius " + radius
+ ", area " + area() + " and circumference "
+ circumference() + ".");
}
public Double circumference() {
return 2 * Math.PI * radius;
}
}
class Rectangle extends Shape {
private Double length, breadth;
public Rectangle(Double length, Double breadth) {
super("Rectangle");
this.length = length;
this.breadth = breadth;
}
@Override
public Double area() {
return length * breadth;
}
public Double perimeter() {
return 2 * length + 2 * breadth;
}
@Override
public void print() {
System.out.println("A " + name + " with length " + length
+ ", breadth " + breadth + ", area " + area()
+ " and perimeter " + perimeter() + ".");
}
}
Circle circle = new Circle(4d);
circle.print();
Rectangle rectangle = new Rectangle(2d, 5.5);
rectangle.print();
DiskEdit
clojure
(defmulti area :Shape)
(defmulti print :Shape)

; Circle methods
(defn circle [r]
{:Shape :Circle
:name "Circle"
:radius r})

(defn circumference [c]
(* 2 Math/PI (:radius c)))

(defmethod area :Circle [c]
(* Math/PI (:radius c) (:radius c)))

(defmethod print :Circle [c]
(println (format "I am a %s with ->" (:name c)))
(println (format "Radius: %.2f" (:radius c)))
(println (format "Area: %.2f" (area c)))
(println (format "Circumference: %.2f" (circumference c))))

; Rectangle methods
(defn rectangle [l b]
{:Shape :Rectangle
:name "Rectangle"
:length l
:breadth b})

(defn perimeter [r]
(+ (* 2 (:length r)) (* 2 (:breadth r))))

(defmethod area :Rectangle [r]
(* (:length r) (:breadth r)))

(defmethod print :Rectangle [r]
(println (format "I am a %s with ->" (:name r)))
(println (format "Length, Width: %.2f, %.2f" (:length r) (:breadth r)))
(println (format "Area: %.2f" (area r)))
(println (format "Perimeter: %.2f" (perimeter r))))

; usage of the "classes"
(let [shapes (list (circle 4.2) (rectangle 2.7 3.1) (rectangle 6.2 2.6) (circle 17.3))]
(doseq [shape shapes]
(print shape)))
DiskEdit
fantom
abstract class Shape
{
const Str name
new make(Str name) { this.name = name }
abstract Float area()
abstract Void print()
}

class Circle : Shape
{
private Float radius

new make(Float radius) : super("circle") { this.radius = radius }
Float circumference() { return 2 * Float.pi * radius }
override Float area() { return Float.pi * radius.pow(2.0f) }
override Void print()
{
echo("I am a $name with radius $radius, area $area
and circumference $circumference")
}
}

class Rectangle : Shape
{
private Float length
private Float breadth

new make(Float length, Float breadth) : super("rectangle")
{
this.length = length
this.breadth = breadth
}
Float perimeter() { return 2 * (length + breadth) }
override Float area() { return length * breadth }
override Void print()
{
echo("I am a $name with length $length, breadth $breadth,
area $area and perimeter $perimeter")
}
}


circle := Circle(4.0f)
circle.print
rectangle := Rectangle(2.0f, 5.5f)
rectangle.print

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