User Guide

Table Of Contents

86 Chapter 4: Using Expressions and Number Signs

To construct a variable name this way, all the text on the left side of the equal sign must be in

quotation marks.

This usage is less efficient than using arrays. The following example has the same purpose as the

previous one, but requires less processing:

Dynamic variable limitation

When you use a dynamic variable name in quotation marks on the left side of an assignment, the

name must be either a simple variable name or a complex name that uses object.property notation

(such as MyStruct.#KeyName#). You cannot use an array as part of a dynamic variable name. For

example, the following code generates an error:

However, you can construct an array index value dynamically from variables without using

quotation marks on the left side of an assignment. For example, the preceding sample code works

if you replace the final line with the following line:

Dynamically constructing structure references

The ability to use associative array notation to reference structures provides a way for you to use

variables to dynamically create structure references. (For a description of associative array

notation, see “Structure notation” on page 109.) Associative array structure notation allows you

to use a ColdFusion expression inside the index brackets. For example, if you have a

productName structure with keys of the form product_1, product_2 and so on, you can use the

following code to display the value of productName.product_3:

Product_3 Name: #ProductName["product_" & prodNo]#

For an example of using this format to manage a shopping cart, see “Example: a dynamic

shopping cart” on page 92.