Question

JAVA

design a class named Rectangle to represent a rectangle. The class contains:

A method named getPerimeter() that returns the perimeter.

• Two double data fields named width and height that specify the width and height of the rectangle. The default values are 1 for both width and height.

• A no-arg constructor that creates a default rectangle.

• A constructor that creates a rectangle with the specified width and height.

• A method named getArea() that returns the area of this rectangle.

• design a class named Rectangle to represent a rectangle. The class contains:

• Two double data fields named width and height that specify the width and height of the rectangle. The default values are 1 for both width and height.

• A no-arg constructor that creates a default rectangle.

• Draw the UML diagram for the class and then implement the class. Write a test program that creates two Rectangle objects-one with width 4 and height 40 and the other with width 3.5 and height 35.9. Display the width, height, area, and perimeter of each rectangle in this order.

• A constructor that creates a rectangle with the specified width and height.

• A method named getArea() that returns the area of this rectangle.

• A method named getPerimeter() that returns the perimeter.

Draw the UML diagram for the class and then implement the class. Write a test program that creates two Rectangle objects-one with width 4 and height 40 and the other with width 3.5 and height 35.9. Display the width, height, area, and perimeter of each rectangle in this order.

please help me fixing the mistake ?

public class Exercise09_01
{
     public static void main (String[] args)
      {
             Rectangle rectangle1 = new Rectangle(4,40);

             Rectangle rectangle2 = new Rectangle(3.5,3.59);
           
             System.out.println("The details of the first rectangel...");
             System.out.println("Width of Rectangle1:" + rectangle1.width);
             System.out.println("Height of Rectangle1:" + rectangle1.height);
             System.out.println("Area of Rectangle1:" + df.format(rectangle1.getArea()));
             System.out.println("Perimeter of Rectangle1:"+ rectangle1.getPerimeter());
             System.out.println();

             System.out.println("The details of the second rectangel...");
             System.out.println("Width of Rectangle2:" + rectangle2.width);
             System.out.println("Height of Rectangle2:" + rectangle2.height);
             System.out.println("Area of Rectangle2:" + df.format(rectangle2.getArea()));
             System.out.println("Perimeter of Rectangle2:"+ rectangle2.getPerimeter());
       }
}
           
public class Rectangle
{
        double width = 1.0;
        double height = 1.0;
   Rectangel() {
       }
   Rectangel(double newWidth, double newHeight)
      {
          width = newWidth;
          height = newHeight;
       }
   double getArea()
     {
   return width * height;
     }
   double getPerimeter()
     {
   return 2*(width + height);
}
}

    

Answer 1

UML Rectangle class digaram

Rectangle width: double height: double +Rectangle () +Rectangle (newWidth:double, newHeight: double) +getArea) double +getPerimeter double

-------------------------------*-------------------------------*-------------------------------*
/**Test java program for Rectangle class*/
//Exercise09_01.java
import java.text.DecimalFormat;
public class Exercise09_01
{
   public static void main (String[] args)
   {
       Rectangle rectangle1 = new Rectangle(4,40);
       Rectangle rectangle2 = new Rectangle(3.5,3.59);

       /**Create an instace of DecimalFormat class*/
       DecimalFormat df=new DecimalFormat("#,##.##");
      
       System.out.println("The details of the first rectangel...");
       System.out.println("Width of Rectangle1:" + rectangle1.width);
       System.out.println("Height of Rectangle1:" + rectangle1.height);
       System.out.println("Area of Rectangle1:" + df.format(rectangle1.getArea()));
       System.out.println("Perimeter of Rectangle1:"+ rectangle1.getPerimeter());
       System.out.println();

       System.out.println("The details of the second rectangel...");
       System.out.println("Width of Rectangle2:" + rectangle2.width);
       System.out.println("Height of Rectangle2:" + rectangle2.height);
       System.out.println("Area of Rectangle2:" + df.format(rectangle2.getArea()));
       System.out.println("Perimeter of Rectangle2:"+ rectangle2.getPerimeter());
   }
}

-------------------------------*-------------------------------*-------------------------------*
//Rectangle.java
public class Rectangle
{
   /**Instance variables */
   double width ;
   double height;
   /*Name of the constructor must match with
   * the name of the class, Rectangle*/
   public Rectangle()
   {
       width=1;
       height=1;
   }
   /*Name of the constructor must match with
   * the name of the class, Rectangle*/
   public Rectangle(double newWidth, double newHeight)
   {
       width = newWidth;
       height = newHeight;
   }
   /**Returns area */
   public double getArea()
   {
       return width * height;
   }
   /**Returns perimeter */
   public double getPerimeter()
   {
       return 2*(width + height);
   }
}/**End of Rectangle class*/

-------------------------------*-------------------------------*-------------------------------*

Sample Output:

The details of the first rectangel...
Width of Rectangle1:4.0
Height of Rectangle1:40.0
Area of Rectangle1:1,60
Perimeter of Rectangle1:88.0

The details of the second rectangel...
Width of Rectangle2:3.5
Height of Rectangle2:3.59
Area of Rectangle2:12.56
Perimeter of Rectangle2:14.18