Copy Constructor in Rectangle Class

Overview

  1. Starting Eclipse
  2. Source Code Structure
  3. Implementing Point Class
  4. Implementing Rectangle Class
  5. Testing
  6. Copy Constructor in Rectangle Class

Eclipse Tips and Tricks

A copy constructor is a constructor with a single argument of the same type as the class. Making a copy of an object requires a special method called a copy constructor. The copy constructor should create an object that is a separate, independent object, but with the instance variables set so that it is an exact copy of the argument object.

You will create a copy constructor in rectangle class. 

public Rectangle(Rectangle original)
{
    upperLeft = new Point(original.upperLeft.getX(),original.upperLeft.getY());
	// Finish the rest of the code for another three instance variables
}

Testing

Uncommenting the last part of the test program in main. Use the same test case in step 6 to test your program. 

Scanner scanner = new Scanner(System.in);
int x = 1;
int y = 1;

System.out.print("Enter the x-coordinate of the upperLeft :");
x = scanner.nextInt();
System.out.print("Enter the y-coordinate of the upperLeft :");
y = scanner.nextInt();

Point upperLeft = new Point(x, y);


System.out.print("Enter the x-coordinate of the lowerLeft :");
x = scanner.nextInt();
System.out.print("Enter the y-coordinate of the lowerLeft :");
y = scanner.nextInt();

Point lowerLeft = new Point(x, y);


System.out.print("Enter the x-coordinate of the lowerRight :");
x = scanner.nextInt();
System.out.print("Enter the y-coordinate of the lowerRight :");
y = scanner.nextInt();

Point lowerRight = new Point(x, y);


System.out.print("Enter the x-coordinate of the upperRight:");
x = scanner.nextInt();
System.out.print("Enter the y-coordinate of the upperRight:");
y = scanner.nextInt();

Point upperRight = new Point(x, y);

Rectangle rectangle = new Rectangle(upperLeft, lowerLeft, lowerRight, upperRight);

System.out.printf("Length of rectangle : %.2f\n", rectangle.getLength());
System.out.printf("Width of rectangle : %.2f\n", rectangle.getWidth());
System.out.printf("Area of rectangle : %.2f\n", rectangle.getArea());
System.out.printf("Perimeter of rectangle : %.2f\n", rectangle.getPerimeter());

//test the copy constructor
Rectangle rectangleNew = new Rectangle(rectangle);

System.out.printf("Length of rectangleNew : %.2f\n", rectangleNew.getLength());
System.out.printf("Width of rectangleNew : %.2f\n", rectangleNew.getWidth());
System.out.printf("Area of rectangleNew : %.2f\n", rectangleNew.getArea());
System.out.printf("Perimeter of rectangleNew : %.2f\n", rectangleNew.getPerimeter());
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