JavaScript Design

Built-in Objects and Their Properties

Several important built-in objects have properties that you need to understand for optimal use with JavaScript. This section examines two key objects: the screen and the window. The window properties examined here are specific to the window object and do not refer to virtually every other object that is a property of the window object.

Reading Screen Properties

When a browser opens an HTML page, it does so with the screen properties determined by the viewer’s equipment. All screen properties are read-only and are static as far as the designer/developer is concerned. The screen object has five cross-browser properties:

							screen.availHeight 
screen.availWidth 
screen.colorDepth 
screen.height 
screen.width