Element Classes

Elements are objects contained within an object. The element classes listed in an object class definition indicate the kinds of elements objects of that class can contain. An object can contain many elements or none, and the number of elements that it contains may change over time. For example, it is possible for a Paragraph object to contain no words. At a later time, the same paragraph might have many words.

Most application and system objects can contain elements. The Finder's Window definition in Table 5-1 has no elements, but the AppleWorks Window definition in Table 5-2 includes Panes, Splits, and other elements.