System information

22 Chapter 2: CFML Basics

In the following examples, the variables are assigned a string literal value. All string literal values

are surrounded by double-quotation marks.

In the next example, ColdFusion uses the values of the my_first_name and my_last_name

variables to set the value for the

my_full_name variable in the last line of code. The ampersand

(

&) string operator joins the variables, and the space surrounded by double-quotation marks (" ")

adds a space between the variables.

Tip: String values assigned to a variable must be enclosed in single-quotation marks (') or double-

quotation marks ("). Numeric or Boolean values assigned to a variable do not require single- or

double-quotation marks.

So far, all the variable examples have shown local variables. Local variables are variables that you

can use only on the current ColdFusion page. The previous example used a variables prefix to

reference an existing variable on the page. Using a prefix when referencing a variable is important

because ColdFusion supports many types of variables. Use the following syntax to reference a

local variable:

variables.variablename

Because ColdFusion lets you use the same name with variables of more than one type,

ColdFusion relies on scope referencing. In scope referencing, you preface the variable’s name with

the scope when you refer to that variable.

Other variables and their scope

Each type of variable that ColdFusion supports has it own scope, or where it can be referenced,

and its own way of referencing that variable type. The following table identifies some of the more

common types of variables and their prefixes:

You will use these other types of variables in Part II of this manual. For additional information

about variables, see CFML Reference.

Scope Prefix Description

Variables

(local variable)

Variables Variables created using a

cfset or cfparam tag. Most often you define

the variable on the current page or on a page that you include using

the

cfinclude tag.

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

processed on the action page.

URL URL Variables passed to a page as URL string parameters.

Query QueryName Variables that have names based on the column names that you select

in the database table. The values are created when you execute the

query that selects data from the database.