Tài liệu Working with Structures

This chapter discusses structures, which are the most complex
and most useful of the complex data types. You learn what structures
are, how to use them, and when to use them.
What is a Structure?
Simply put, a structure is a container for other variables. Structures
are like arrays in that they contain programmatically addressable elements,
but structures name each element rather than simply assigning
them numeric positions. Graphically, a structure looks as shown
in Figure 15-1.
Figure 15-1: A graphical representation of
a structure.
Notice that each element in a structure has a name. Always remember
that each element in an array has a number, while structure elements
have names. You see how naming each element is useful
throughout the chapter.
Creating a Structure
As are arrays, structures are complex objects with a specific initialization
function, as the following example shows:
<cfset myStruct = StructNew()>
StructNew() doesn’t take any arguments, because structures do not
have a simple dimension. As you will see in the section “Nested
Structures” later in this chapter, structures may have arbitrarily complex
dimensions.
If myStruct currently contains a value, StructNew()destroys the old
value and replaces it with an empty structure.