MACROMEDIA ColdFusion MX, Руководство по разработке

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Strings 61
Complex data types
Arrays, structures, and queries are ColdFusion built-in complex data types. Structures and queries
are sometimes referred to as objects, because they are containers for data, not individual data
values.
For details on using arrays and structures, see Chapter 5, “Using Arrays and Structures,”
on page 103 .
Arrays
Arrays are a way of storing multiple values in a table-like format that can have one or more
dimensions. To create an array and specify its initial dimensions, use the ColdFusion
ArrayNew
function. For example, the following line creates an empty two-dimensional array:
<cfset myarray=ArrayNew(2)>
You reference elements using numeric indexes, with one index for each dimension. For example,
the following line sets one element of a two-dimensional array to the current date and time:
<cfset myarray[1][2]=Now()>
The
ArrayNew
function can create arrays with up to three dimensions. However, there is no limit
on array size or maximum dimension. To create arrays with more than three dimensions, create
arrays of arrays.
After you create an array, you can use functions or direct references to manipulate its contents.
When you assign an existing array to a new variable, ColdFusion creates a new array and copies
the old array’s contents to the new array. The following example creates a copy of the original
array:
<cfset newArray=myArray>
For more information on using arrays, see Chapter 5, “Using Arrays and Structures,”
on page 103 .
Structures
ColdFusion structures consist of key-value pairs, where the keys are text strings and the values can
be any ColdFusion data type, including other structures. Structures let you build a collection of
related variables that are grouped under a single name. To create a structure, use the ColdFusion
StructNew
function. For example, the following line creates a new, empty, structure called depts :
<cfset depts=StructNew()>
You can also create a structure by assigning a value in the structure. For example, the following
line creates a new structure called
MyStruct with a key, MyValue , equal to 2:
<cfset MyStruct.MyValue=2>
Note: In previous ColdFusion versions, this line created a Variables scope variable named
"MyStruct.MyValue" with the value 2.
After you create a structure, you can use functions or direct references to manipulate its contents,
including adding key/value pairs.