Flex: Looping through array of arrays

Question

I am attempting to build an array of arrays that will with the following syntax. My output is definitely not what I am trying to achieve. Here is my code:

var labs:ArrayCollection = new ArrayCollection();
    var sets:ArrayCollection = new ArrayCollection();

    var labsArray:Array = ["ProDPI","WHCC","Tin"];
    var setsArray:Array = ["Set1","Set2","Set3"];

    var folders:ArrayCollection = new ArrayCollection();
    var foldersArray:Array = [labsArray, setsArray];

    var objFolderBuild:Object = new Object;

        for (var i:int = 0; i< foldersArray.length;i++) {
                for (var j:int = 0; j < foldersArray[i].length; j++) {
                    objFolderBuild.labName = foldersArray[i][j];
                    folders.addItem(objFolderBuild);
                }
        }
labFolderList.labelField="labName";
labFolderList.dataProvider=folders;
setFolderList.labelField="setName";
setFolderList.dataProvider=folders;

My output is coming out as 6 references to "Set3". There is obviously something wrong with my for loops, but I can't figure it out. Any ideas would be a great help.

Answer 1

I threw together this quick app to prove that your code is properly tracing out the foldersArray[i][j]. It's 90% the code from your app.

However, I want to point out that the objFoldersBuild object is only created once. So what you do each time through the loop is change the value of an existing object's property and add it to your folders ArrayCollection. You have an ArrayCollection with multiple copies of the same exact object. The answer is to create a new object each time through the loop.

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                       xmlns:s="library://ns.adobe.com/flex/spark" 
                       xmlns:mx="library://ns.adobe.com/flex/mx" preinitialize="windowedapplication1_preinitializeHandler(event)">
    <fx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.events.FlexEvent;

            protected function windowedapplication1_preinitializeHandler(event:FlexEvent):void
            {
                var labs:ArrayCollection = new ArrayCollection();
                var sets:ArrayCollection = new ArrayCollection();

                var labsArray:Array = ["ProDPI","WHCC","Tin"];
                var setsArray:Array = ["Set1","Set2","Set3"];

                var folders:ArrayCollection = new ArrayCollection();
                var foldersArray:Array = [labsArray, setsArray];

                var objFolderBuild:Object = new Object;

                for (var i:int = 0; i< foldersArray.length;i++) {
                    for (var j:int = 0; j < foldersArray[i].length; j++) {
                        trace(foldersArray[i][j]);
                                objFolderBuild  = new Object;
                        objFolderBuild.labName = foldersArray[i][j];
                        folders.addItem(objFolderBuild);
                    }
                }
/*              labFolderList.labelField="labName";
                labFolderList.dataProvider=folders;
                setFolderList.labelField="setName";
                setFolderList.dataProvider=folders; */
            }

        ]]>
    </fx:Script>
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
</s:WindowedApplication>