MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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72 Chapter 3: Using ColdFusion Variables
Example 2
True AND 2 * 3
Result value as string: "YES"
Explanation: 6 is converted to Boolean True because it is nonzero; True AND True is True.
Example 3
"Five is " & 5
Result value as string: "Five is 5"
Explanation: 5 is converted to the string "5".
Example 4
DateFormat("October 30, 2001" + 1)
Result value as string: "31-Oct-01"
Explanation: The addition operator forces the string "October 30, 2001" to be converted to a
date-time object and then to a number. The number is incremented by one. The DateFormat
function requires its argument to be a date-time object; thus, the result of the addition is
converted to a date-time object. One is added to the date-time object, moving it ahead by one day
to October 31, 2001.
About scopes
Variables differ in the source of the data, the places in your code where they are meaningful, and
how long their values persist. These considerations are generally referred to as a variable’s
scope .
Commonly used scopes include the Variables scope, the default scope for variables that you
create, and the Request scope, which is available for the duration of an HTTP request.
Note: User-defined functions also belong to scopes. For more information, see Chapter 10,
“Specifying the scope of a function,” on page 206 .
Scope types
The following table describes ColdFusion scopes:
Scope Description
Variables
(local) The default scope for variables of any type that are created with the
cfset
and
cfparam
tags. A local variable is available only on the page on which it is created
and any included pages (see also the Caller scope).
Form Contains variables passed from a Form page to its action page as the result of
submitting the form. (If you use the HTML
form
tag, you must use
method="post"
.)
For more information, see Chapter 26, “Retrieving and Formatting Data,”
on page 559 .