Join Two Arrays in ColdFusion

Question

Is there a built-in way to join two arrays in ColdFusion, similar to JavaScript\'s array.concat()?

Answer 1

I took this from Ben Nadel and used it to perform encryption and hashing. Worked like a charm!

<cfscript>
    // Note: BinaryDecode/CharsetDecode return java arrays. 
    // Unlike CF arrays, java arrays are immutable, 
    // so the Java addAll(..) method to merge arrays won't work here. 
    // http://stackoverflow.com/a/10760835/104223

    // function to merge immutable arrays the long way
    function mergeArrays( array1, array2 ){
        var i = 0;
        var newArray = [];
        for (i = 1; i <= arrayLen(arguments.array1); i++) {
            arrayAppend(newArray, arguments.array1[i]);
        }
        for (i = 1; i <= arrayLen(arguments.array2); i++) {
            arrayAppend(newArray, arguments.array2[i]);
        }
        return newArray;
    }


    //convert the saltArray string and CustomerID string to UTF-8 byte arrays.
    saltByteArray = charsetDecode(salt, "utf-8");
    CustomerIdByteArray = charsetDecode(CustomerId, "utf-8");

    //create a new byte array consisting of the CustomerId bytes
    //appended with the salt bytes by merging the two binary arrays 
    //via custom function, mergeArrays
    mergedBytes = mergeArrays( CustomerIdByteArray, saltByteArray );
</cfscript>

Answer 2

You can easily concatenate two lists like this:

<cfset combolist = ListAppend(lista,listb, ",")>

So, first convert your two arrays to lists using ArrayToList(). Combine the two lists with the ListAppend() and then convert the answer back to an array with ListToArray().

I don't know how efficient this is, but the code is very simple. I'd love to use the arrayAppend() but I'm in ColdFusion 8.

Answer 3

CF10+, use

arrayAppend(array1, array2, true);

https://helpx.adobe.com/coldfusion/cfml-reference/coldfusion-functions/functions-a-b/arrayappend.html

Answer 4

In javascript array.join(s) creates a string out of all of the elements of the array separated by the delimiter s. A similar function to this in ColdFusion is the ArrayToList function. As far as appending an array to another I don't believe there is a CF function for that. Check http://livedocs.adobe.com/coldfusion/8/htmldocs/help.html?content=functions-pt0_03.html#3473387 to see the list of Array functions in CF. Or try something like this:

<cfscript>
   for(index = 1; index LTE ArrayLen(array2); i = i + 1) {
      ArrayAppend(array1, array2[i]);
  }
</cfscript>

Answer 5

Its kinda dumb how coldfusion misses many basic functions that one would expect from a scripting language. Here's one I had to write quickly.

<cffunction name="mergeArrays" returntype="array" >
    <cfargument name="array1" type="array" required="true" >
    <cfargument name="array2" type="array" required="true" >

    <cfset arrayResult = arrayNew(1) >
    <cfloop array="#array1#" index="elem">
        <cfset arrayAppend(arrayResult,elem) >
    </cfloop>

    <cfloop array="#array2#" index="elem">
        <cfset arrayAppend(arrayResult,elem) >
    </cfloop>

    <cfreturn arrayResult>
</cffunction>

Answer 6

If you're using Railo, you can use ArrayMerge (E.g. <cfset NewArray=ArrayMerge(FirstArray,SecondArray)>).