Question

Java

Instructions of assignment:

Inside 1st class

- Find the int width and height of a rectangle; include methods to set and get the width and height; and a method to calculate and return the area

Inside 2nd class

- Use an ArrayList to store 10 unique dimensions of the rectangle class

- Set the width & height using a constructor or setter methods

- Create a bubble sort algorithm list inside a method to set the areas in descending order; print the areas using a for loop; store the areas in new int array

Answer 1

Rectangle.java

public class Rectangle {

   // Data members
   private int width;
   private int height;

   // Constructor to initialize data members
   public Rectangle(int width, int height) {
       this.width = width;
       this.height = height;
   }

   // Setter and getter method for data members
   public int getWidth() {
       return width;
   }

   public void setWidth(int width) {
       this.width = width;
   }

   public int getHeight() {
       return height;
   }

   public void setHeight(int height) {
       this.height = height;
   }

   // Calculate area and return
   public int area() {
       return height * width;
   }
}

RectList.java

import java.util.ArrayList;

public class RectList {

   public static void main(String[] args) {
       // Create an array list and add 10 rectangle objects to it
       ArrayList<Rectangle> rect_list = new ArrayList<Rectangle>();
       rect_list.add(new Rectangle(2, 3));
       rect_list.add(new Rectangle(12, 3));
       rect_list.add(new Rectangle(5, 4));
       rect_list.add(new Rectangle(2, 1));
       rect_list.add(new Rectangle(10, 13));
       rect_list.add(new Rectangle(7, 3));
       rect_list.add(new Rectangle(3, 8));
       rect_list.add(new Rectangle(12, 13));
       rect_list.add(new Rectangle(12, 3));
       rect_list.add(new Rectangle(1, 3));

       // Create an array to store area of rectangles
       int areaArray[] = new int[10];
       int length = rect_list.size();

       // Iterate over arraylist, get area and store in areaArray
       for (int i = 0; i < length; i++) {
           areaArray[i] = rect_list.get(i).area();
       }

       // Bubble sort to sort areaArray in descending order
       for (int i = 0; i < length - 1; i++) {
           for (int j = i + 1; j < length; j++) {
               // Compare each element with every other element
               // if area at i < area at j
               // swap them
               if (areaArray[i] < areaArray[j]) {
                   int temp = areaArray[i];
                   areaArray[i] = areaArray[j];
                   areaArray[j] = temp;
               }
           }
       }

       // Iterate over areaArray and print area
       System.out.println("Area in descending order: ");
       for (int i = 0; i < length; i++) {
           System.out.print(areaArray[i] + " ");
       }
   }
}

OUTPUT