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M
mmcarthey
Participant
July 22, 2010
Question

Using ListAppend and dynamic variables

  • July 22, 2010
  • 2 replies
  • 824 views

Hello all,

I have an example that is causing me trouble.

If I do the following, things work as expected.

CODE:

<cfoutput query="Customers">

<cfset var2 = listAppend(var2, #Customers.accno#)>

</cfoutput>

OUTPUT: #var2#

RESULTS: 553,610

The problem is that my output changes unexpectedly if I change my code.

CODE:

<cfoutput query="Customers">

<cfset var#Customers.key# = listAppend(var#Customers.key#, #Customers.accno#)>

</cfoutput>

OUTPUT: var#Customers.key#

RESULTS: var2,610

For a reason I haven't been able to determine, the ListAppend (or simple concatenate for that matter) is pre-pending the name of the dynamic variable to the list.  I can only assume it is the manner in which ColdFusion evaluates the statement but I'm not sure how to work around it.

Thanks for any help!

    This topic has been closed for replies.

    2 replies

    A
    Adam Cameron.
    Inspiring
    July 22, 2010
    <cfoutput query="Customers">

    <cfset var#Customers.key# = listAppend(var#Customers.key#, #Customers.accno#)>

    </cfoutput>

    Which version of CF were you able to get that code to run?

    The <cfset> line has two syntax errors in it: both reverences to the dynamic variable you're trying to create are invalid, and will not compile on any version of CF I know of.

    ??

    --

    Adam

    ilssac
    ilssac
    Inspiring
    July 22, 2010

    CODE:

    <cfoutput query="Customers">
         <cfset variables["var" & Customers.key] = listAppend(variables["var" & Customers.key], variables.Customers.accno)>
    </cfoutput>

    Array notation is a much more reliable way to work with dynamic variable naming.

    M
    mmcartheyAuthor
    Participant
    July 22, 2010

    I don't believe I've seen the variables[] array.  Is that a built-in construct?

    I'm assuming there's some magic there since without it the code functions just as in my original post.

    Thanks

    ilssac
    ilssac
    Inspiring
    July 22, 2010

    mmcarthey wrote:

    I don't believe I've seen the variables[] array.  Is that a built-in construct?

    I'm assuming there's some magic there since without it the code functions just as in my original post.

    Thanks

    Yes, starting with CF 6, when ColdFusion was ported to a Java base, all the scopes of ColdFusion are structure arrays, including the variables[] scope which is where unscoped variables live.

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