RectangleDemo app class

import javax.swing.JOptionPane;
/**
   This program is an application class,
   It is used to test/drive the Rectangle logic class

*/

public class RectangleDemo
{
   public static void main(String[] args)
   {
      // Create a Rectangle object, passing 5.0 and
      // 15.0 as arguments to the constructor.
      double width = 1, length;
      Rectangle lot, house, gardenShed, box;
      lot = new Rectangle(100, 200);
      house = new Rectangle(40.0, 50.0);
      gardenShed = new Rectangle(4.0, 8.0);
      System.out.println("Lot\narea:\t "+lot.calcArea() +
            "\tperimiter: " + lot.calcPerimeter()+"\n\nBuildings:");
      System.out.println("Garden Shed\n area:\t "+gardenShed.calcArea() +
            "\t\tperimiter: " + gardenShed.calcPerimeter());
      System.out.println("House\n area:\t "+house.calcArea() +
            "\t\tperimiter: " + house.calcPerimeter());
      System.out.println ("\nArea left to build on "+
            (lot.calcArea() - house.calcArea() - gardenShed.calcArea()));
      /* temp
      while (width > 0) {
        if ((width = acceptDub ("Rectangle width:")) >  0) {
            if ((length = acceptDub ("Rectangle length:")) > 0) {
                box = new Rectangle(length, width);
                // Display the length.
                System.out.println("The box's length is " +
                         box.getLength());
                // Display the width.
                System.out.println("The box's width is " +
                         box.getWidth());
                // Display the area.
                System.out.println("The box's area is " +
                         box.calcArea());
                         // Display the area.
                System.out.println("The box's perimiter is " +
                         box.calcPerimeter());
                }
        }
      }
*/
        System.out.println("Bye! ");
   }//main()

   public static double acceptDub(String msg) {
       String numIn =  JOptionPane.showInputDialog(msg);
       double numOut = 0;
       try {
           numOut = Double.parseDouble(numIn);
       } catch (NullPointerException|NumberFormatException e) {
           System.out.println("Invalid number, can't convert");
       }
       return numOut;
   } //acceptDub(0
} // RectangleDemo