Restore

Labs/Lab6/Lab6_2230026071/Question5/.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER">
+		<attributes>
+			<attribute name="module" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

Labs/Lab6/Lab6_2230026071/Question5/.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Question5</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

Labs/Lab6/Lab6_2230026071/Question5/.settings/org.eclipse.core.resources.prefs

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+eclipse.preferences.version=1
+encoding/<project>=UTF-8

Labs/Lab6/Lab6_2230026071/Question5/src/Circle.java

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+
+public class Circle extends Shape{
+	//instance variable
+	private double radius;
+	
+	//constructor
+	public Circle(double x, double y, double radius) {
+		super(x, y);
+		this.radius = radius;
+	}
+	
+	//method
+	public double area() {
+		return Math.PI * this.radius * this.radius;
+	}
+	
+	//test
+	public static void testCircle() {
+		Circle c = new Circle(1.2, 3.4, 4.0);
+		// getX and getY are inherited from Shape.
+		// area comes from Circle itself.
+		System.out.println(c.getX() == 1.2);
+		System.out.println(c.getY() == 3.4);
+		System.out.println(c.area() == Math.PI * 16.0);
+		}
+}

Labs/Lab6/Lab6_2230026071/Question5/src/Dot.java

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+
+public class Dot extends Shape {
+	//constructor
+	public Dot(double x, double y) {
+		super(x, y);
+	}
+	
+	//method
+	public double area() {return 0.0;}
+	
+	//test
+	public static void testDot() {
+		Dot d = new Dot(1.2, 3.4);
+		// getX and getY are inherited from Shape.
+		// area comes from Dot itself.
+		System.out.println(d.getX() == 1.2);
+		System.out.println(d.getY() == 3.4);
+		System.out.println(d.area() == 0.0);
+		}
+}

Labs/Lab6/Lab6_2230026071/Question5/src/ManyShapes.java

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+import java.util.ArrayList;
+
+public class ManyShapes {
+	//instance variables
+	private ArrayList allshapes;
+	
+	//constructor
+	public ManyShapes() {
+		this.allshapes = new ArrayList();
+	}
+	
+	//method
+	public void addShape(Shape s) {
+		allshapes.add(s);
+	}
+	
+	public void listAllShapes() {
+		for(int i = 0; i < allshapes.size(); ++i) {
+			Shape o = (Shape) allshapes.get(i);
+			System.out.println("Shape has area " + o.area());
+		}
+	}
+	
+	//test
+	public static void testManyShapes() {
+		ManyShapes m = new ManyShapes();
+		m.addShape(new Circle(1.2, 3.4, 4.0)); // Upcast from Circle to Shape.
+		m.addShape(new Dot(1.2, 3.4)); // Upcast from Dot to Shape.
+		m.addShape(new Rectangle(1.2, 3.4, 4.0, 5.0)); // Upcast from Rectangle to Shape.
+		m.addShape(new Shape(1.2, 3.4));
+		m.addShape(new Square(1.2, 3.4, 5.0)); // Upcast from Square to Shape.
+		m.listAllShapes();
+		}
+}

Labs/Lab6/Lab6_2230026071/Question5/src/Rectangle.java

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+
+public class Rectangle extends Shape {
+	//instance variables
+	private double width;
+	private double length;
+	
+	//constructor
+	public Rectangle(double x, double y, double width, double length) {
+		super(x, y);
+		this.width = width;
+		this.length = length;
+	}
+	
+	//method
+	public double area() {
+		return this.width * this.length;
+	}
+	
+	//test
+	public static void testRectangle() {
+		Rectangle r = new Rectangle(1.2, 3.4, 4.0, 5.0);
+		// getX and getY are inherited from Shape.
+		// area comes from Rectangle itself.
+		System.out.println(r.getX() == 1.2);
+		System.out.println(r.getY() == 3.4);
+		System.out.println(r.area() == 20.0);
+		}
+}

Labs/Lab6/Lab6_2230026071/Question5/src/Shape.java

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+
+public class Shape {
+	//instance variables
+	private double x;
+	private double y;
+	
+	//constructor
+	public Shape(double x, double y) {
+		this.x = x;
+		this.y = y;
+	}
+	
+	//methods
+	public double getX() {return this.x;}
+	
+	public double getY() {return this.y;}
+	
+	public double area() {
+		System.out.println("An unknown shape has an unknown area!");
+		return -1.0;
+	}
+	
+	//test
+	public static void testShape() {
+		Shape s = new Shape(1.2, 3.4);
+		System.out.println(s.getX() == 1.2);
+		System.out.println(s.getY() == 3.4);
+		System.out.println(s.area() == -1.0); // Will print an error message too.
+		}
+
+}

Labs/Lab6/Lab6_2230026071/Question5/src/Square.java

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+
+public class Square extends Rectangle {
+	//constructor
+	public Square(double x, double y, double size) {
+		super(x, y, size, size);
+	}
+	
+	//Square dose not need to have its own area() method
+	
+	//test
+	public static void testSquare() {
+		Square s = new Square(1.2, 3.4, 5.0);
+		// getX and getY are inherited from Shape.
+		// area is inherited from Rectangle.
+		System.out.println(s.getX() == 1.2);
+		System.out.println(s.getY() == 3.4);
+		System.out.println(s.area() == 25.0);
+		}
+
+}

Labs/Lab6/Lab6_2230026071/Question5/src/Start.java

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+
+public class Start {
+
+	public static void main(String[] args) {
+		Shape.testShape();
+		Circle.testCircle();
+		Dot.testDot();
+		Rectangle.testRectangle();
+		Square.testSquare();
+		ManyShapes.testManyShapes();
+	}
+
+}