User Guide

14 Chapter 2 Writing Your First ColdFusion Application

you can write:

I’d like to talk to someone in #Variables.Department#.

Some variable scopes, such as the local scope, do not require the scope identifier

prefix, while others do. However, it is good programming practice to use prefixes for

most or all scopes. This helps to better identify each variable’s use and can prevent

multiple uses of the same name. This book uses the scope prefix for all variables

except for local variables.

The following table lists some of the more common types of variable scopes and the

prefixes that you use to identify the variables. Other chapters in this book discuss

additional scope types. The CFML Reference has a complete list of scope types, their

identifiers, and how they are used.

Using the pound sign (#)

You surround a ColdFusion variable or function with pound signs (#) to tell the

ColdFusion Server that it is not plain text. You only need to use pound signs in

limited circumstances, particularly in the cfoutput and cfquery tag blocks. You do

not need to use pound signs when you create a variable, assign it a value, or use it in

a ColdFusion expression or as a parameter in a ColdFusion function.

Note

Remember that ColdFusion cannot interpret anything, including variables, that is

not inside a ColdFusion tag or tag block.

The following table illustrates the basic use of pound signs. For a detailed description

of the use of pound signs, see CFML Reference.

Scope type Prefix Description

Local (or

Variables)

Variables Variables created using cfset or cfparam, with or without

specifying the scope prefix. You must define the variable

on the current page or a page you include using

cfinclude.

Form Form Data entered in tags in an HTML form or ColdFusion

cfform tag block and processed on an action page.

URL URL Variables passed to a page as URL query string

parameters.

CFML code Results

cfset Department="Sales">

The variable named Department is created

and the value is set to Sales.

I’d like to talk to someone in

Department.

</cfoutput>

ColdFusion does not treat Department as a

variable because it is not surrounded by

pound signs. The HTML page displays:

I’d like to talk to someone in Department.