Question about ArrayMap(), .map(), .filter(), and .reduce()

Not so fast, fellers. :-) You can indeed use those functions in tags.

And while it’s true that an *unnamed* callback function won’t work in tags (I don’t think), I can say with confidence that a named one will—and that can be defined in cffunction (or script), then used in such functions.

I show an example of doing an arraymap in both script and tags, running at cffiddle here​.

But to save you having to go there, and in case it may be better searched/found by folks in the future, here are the two variants.

The first is in fact code you wrote and offered, Wolf (here: https://coldfusion.adobe.com/2017/10/map-reduce-and-filter-functions-in-coldfusion/)

<cfscript>

animals=["cat","dog","horse","lion","tiger"];

arrayMap(animals,function(item,index){

writeOutput("Animal number " & index & " is a " & item & "<br />");

});

</cfscript>

And here it is in all its “tag glory”:

<cffunction name="map">

    <cfargument name="item">

    <cfargument name="index">

    <cfoutput>Animal number #index# is a #item# <br /></cfoutput>

</cffunction>

<cfset animals=["cat","dog","horse","lion","tiger"]>

<cfset arrayMap(animals,map)>

And please, no comments from the tag-hating peanut gallery. That’s really not the point of this thread.