Class Object and Method

Class using constructor

Here's a of SimpleRectangle, called Rectangle, that contains four constructors, a method to "move" the rectangle, a method to compute the area of the rectangle, and a finalize method to provide for clean up:

public class Rectangle

{

public int width = 0;
public int height = 0;
public Point origin;
// four constructors
public Rectangle()
{
origin = new Point(0, 0);
}

public Rectangle(Point p)
{
origin = p;
}

public Rectangle(int w, int h)
{
this(new Point(0, 0), w, h);
}

public Rectangle(Point p, int w, int h)
{
origin = p;
width = w;
height = h;
}

// a method for moving the rectangle

public void move(int x, int y)
{
origin.x = x;
origin.y = y;
}

// a method for computing the area of the rectangle

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

// clean up!

protected void finalize() throws Throwable
{
origin = null;
super.finalize();
}

}

Here the four constructors allow for different types of initialization.