User Guide

112 Chapter 5: Using Arrays and Structures
Creating structures using a function
You can create structures by assigning a variable name to the structure with the
StructNew
function as follows:
<cfset mystructure=StructNew()>
For example, to create a structure named departments, use the following syntax:
<cfset departments=StructNew()>
This creates an empty structure to which you can add data.
Use this technique to create structures if your application must run on ColdFusion server versions
5 and earlier.
Adding data elements to structures
You add an element to a structure by assigning the element a value or by using a ColdFusion
function. It is cleaner and more efficient to use direct assignment, so only this technique is
described.
You add structure key-value pairs by defining the value of the structure key, as shown in the
following example:
<cfset myNewStructure.key1="A new structure with a new key">
<cfdump var=#myNewStructure#>
<cfset myNewStructure.key2="Now I’ve added a second key">
<cfdump var=#myNewStructure#>
Updating values in structures
You can update structure element values by assignment or by using the
StructUpdate function.
Direct assignment results in simpler code than using a function, so only the assignment technique
is described.
To update a structure value, assign the key a new value. For example, the following code uses
cfset and object.property notation to create a new structure element called departments.John,
and changes John’s department from Sales to Marketing. It then uses associative array notation to
change his department to Facilities. Each time the department changes, it displays the results:
<cfset departments=structnew()>
<cfset departments.John = "Sales">
<cfoutput>
Before the first change, John was in the #departments.John# Department<br>
</cfoutput>
<cfset Departments.John = "Marketing">
<cfoutput>
After the first change, John is in the #departments.John# Department<br>
</cfoutput>
<cfset Departments["John"] = "Facilities">
<cfoutput>
After the second change, John is in the #departments.John# Department<br>
</cfoutput>