Function ArrayIsDefined() in CF8

This is a new function added in CF8, this function determines whether an array element is defined. This returns true, if the array element is defined (exists); false, otherwise.

Function syntax

ArrayIsDefiend(array, elementIndex)  

Parameters

Parameter	Description
array	Name of a one dimensional array, or the array name and indexes into higher-order dimensions of a multidimensional array.
elementIndex	Index of the element in a one dimensional array, or the index of the element in the final dimension of a multidimensional array.

Usage

To test the existence of an element in a multidimensional array, specify all but the last dimension of the array in the first parameter. For example, the following line tests the existence of element MyArray[2][4][1]:

ArrayIsDefined(MyArray[2][4], 1)  

Example

<h3>ArrayIsDefined Example</h3> <!--- Create a sparse new array. ---> <cfset MyArray = ArrayNew(1)> <!--- Populate an element or two. ---> <cfset MyArray[1] = "Test"> <cfset MyArray[3] = "Other Test">  <cfoutput>     <!--- Display the contents of the array. --->     <p>Your array contents are:     <cfdump var="#MyArray#"></p>          <!--- Check if an existing element is defined. --->     <p>Does element 3 exist?:&nbsp;     #ArrayIsDefined(MyArray, 3)#</p>          <!--- Check if a non-existent element is defined. --->     <p>Does element 2 exist?&nbsp;     #ArrayIsDefined(MyArray, 2)# </cfoutput>