We construct objects in previous chapters but we did not code constructors. So how did we do that?

For any class without coded constructor(s), Java will automatically add what is called a "default constructor". It is not visible, but it is present and usable.

Here we show what a default constructor looks like. Note that it does no initialization.
	public Rectangle() {
	}

When you have no constructors coded in a class, it is generally a better idea to add a no-arg constructor. That way you can assure proper initialization is done.

Example usage:
Rectangle rec;
rec3 = new Rectangle();