Adobe 38043740 - ColdFusion Standard - Mac Development Manual page 1092

DEVELOPING COLDFUSION 9 APPLICATIONS
Using Web Elements and External Objects
Basic data types
WDDX can represent the following basic data types:
Data type Description
Null Null values in WDDX are not associated with a type such as number or string. The tag converts WDDX Nulls to
empty strings.
Numbers WDDX documents use floating-point numbers to represent all numbers. The range of numbers is restricted to
+/-1.7E+/-308. The precision is restricted to 15 digits after the decimal point.
Date-time values Date-time values are encoded according to the full form of ISO8601; for example, 2002-9-15T09:05:32+4:0.
Strings Strings can be of arbitrary length and must not contain embedded nulls. Strings can be encoded using double-
byte characters.
Complex data types
WDDX can represent the following complex data types:
Data type Description
Array Arrays are integer-indexed collections of objects of arbitrary type. Because most languages start array indexes at 0,
while CFML array indexes start at 1, working with array indexes can lead to nonportable data.
Structure Structures are string-indexed collections of objects of arbitrary type, sometimes called associative arrays. Because
some of the languages supported by WDDX are not case-sensitive, no two variable names in a structure can differ only
in their case.
Recordset Recordsets are tabular rows of named fields, corresponding to ColdFusion query objects. Only simple data types can
be stored in recordsets. Because some of the languages supported by WDDX are not case-sensitive, no two field names
in a recordset can differ only in their case. Field names must satisfy the regular expression [_A-Za-z][_.0-9A-Za-z]*
where the period (.) stands for a literal period character, not "any character".
Binary The binary data type represents strings (blobs) of binary data. The data is encoded in MIME base64 format.
Data type comparisons
The following table compares the basic WDDX data types with the data types to which they correspond in the
languages and technologies commonly used on the web:
WDDX CFML
null N/A
boolean Boolean
number Number
dateTime DateTime
string String
array Array
XML Java
Schema
N/A null
boolean java.lang.Boolean
number java.lang.Double
dateTime java.lang.Date
string java.lang.String
N/A java.lang.Vector
Last updated 1/20/2012
ECMAScript/ COM
JavaScript
null VT_NULL
boolean VT_BOOL
number VT_R8
Date VT_DATE
string VT_BSTR
Array VT_ARRAY | VT_VARIANT
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