Programming ColdFusion MX, 2nd Edition

Variables

A variable is a name associated with a data value; it is common to say that a variable stores or contains a value. Variables allow you to store and manipulate data in your applications; they are called variables because the values they represent can change throughout the life of an application. In ColdFusion, you don’t have to explicitly declare your variables, as you do in a language such as C++. Additionally, ColdFusion variables are typeless, meaning that you can assign a value of any datatype (string, numeric, Boolean, object, etc.) to any variable.

Variable Names

The following rules and guidelines apply to variable names in CFML:

• Variable names must begin with a letter, an underscore, or the Unicode currency symbol ($) and can contain only letters, numbers, underscores, and Unicode currency symbols. Variable names can’t contain spaces. For example, Test, MyVariable, My_variable, MyVariable1, and MyDescriptive_var2 are all valid ColdFusion variables, while 4C, My Variable, Phone#, and A/P aren’t. Note that the addition of the Unicode currency symbol is new in ColdFusion MX.

• In ColdFusion MX, you cannot use compound variable names delimited with a period, such as Employee.Name. In previous versions of ColdFusion, compound variable names were allowed. In ColdFusion MX, the same syntax is used to automatically create a structure with a specific key and assign a value to that key. For example, <cfset Employee.Name="Pere Money"> creates a structure named Employee ...