The Tangled Web

Standard Object Hierarchy

The JavaScript execution environment is structured around an implicit root object, which is used as the default namespace for all global variables and functions created by the program. In addition to a handful of language-mandated built-ins, this namespace is prepopulated with a hierarchy of functions that implement input and output capabilities in the browser environment. These capabilities include manipulating browser windows (open(...), close(), moveTo(...), resizeTo(...), focus(), blur(), and such); configuring JavaScript timers (setTimeout(...), setInterval(...), and so on); displaying various UI prompts (alert(...), prompt(...), print(...)); and performing a variety of other vendor-specific and frequently risky ...