Assigning dynamic/unique variable names in a for loop in AS3

Actionscript 3, Flash

Assigning dynamic variable names to objects created in a for loop in AS3.

You have to get very creative to search these questions on google because words like “for” and “loop” are so utterly common.

If you have a loop in AS3 creating multiple variables but need them to have unique names (for later modification) you need to create something like an array to store the references to the variables.

For example, anything you create in a for loop is a temporary reference. It disappears after the loop is complete, and whatever objects were created stick around in the displayObject.

In my situation I had a loop creating my navigation elements, but needed to position each X value separately.

Here is the method I used to keep the references to these variables:

private var mcArray:Array = new Array();  // array that holds references
private function myfunction():void{
	for (var i:int=0; i<2; i++) { 
		var movieClip:MovieClip = new MovieClip(); // the temporary variable
		mcArray[i] = movieClip; // store reference to temporary variable in array

Now, to use those references:

// or
// --
for (var i:int=0; i<2; i++) {
	mcArray[i].foo = bar;

To be absolutely clear, the above example creates two MovieClips according to the loop (while i < 2), and places each MovieClip in the mcArray array at index i (which we have defined as the integer counting the loop).

Now if I wanted to access those individual MovieClips I could use the mcArray to do so.


I could also loop through the array to apply an animation to each item. The possibilities are endless when you use this basic concept!

Generate 1000 triangles. Animate each one to a random color and rotation.


40 thoughts on “Assigning dynamic/unique variable names in a for loop in AS3

  1. Thanks so much for this. I’ve been trying to do this all night. I couldn’t work out how to refer back to the movieclips I’d made and putting them into an array was perfect! 😀

  2. Why do you put addChild there? I don’t know ActionScript but I would have figured to do it like this:

    mcArray[i] = movieClip;

    I would have thought to do it like this:

  3. thank you! I was going insane trying to figure this out coming from AS2. It forms the basis for everything so thank you.

  4. This seems also a possible way to be able to set to null objects removed from the display list created within loops? – as in:

    or is there a simpler way?

  5. I have following path to some movieclips.
    this.vote1.v0.addEventListener(MouseEvent.CLICK, SaveVote);
    this.vote1.v1.addEventListener(MouseEvent.CLICK, SaveVote);
    this.vote1.v2.addEventListener(MouseEvent.CLICK, SaveVote);
    this.vote1.v3.addEventListener(MouseEvent.CLICK, SaveVote);
    this.vote1.v4.addEventListener(MouseEvent.CLICK, SaveVote);

    Who do i make this with a for loop?

  6. Thanks for the great tip, I found it very useful. How could I modify this so I can add a movieclip to a 2-d array? I’m trying to create a grid of tile movieclips and I want to be able to add another clip to coordinates within the grid. I’d imagine it would end with something like:

    Any help would be appreciated.

    1. You want to associate one MC to an array coordinate?

      I’m pretty rusty here, but how about..

      //define 5x5 2d array
      2dArray = new Array();
      2dWidth = 5;
      2dHeight = 5;

      for (var i:int=0; i<2dHeight.length; i++) {
      2dArray[i] = new Array();
      for (var ii:int=0; i<2dWidth.length; ii++) {
      2dArray[i][ii] = new Array();
      2dArray[i][ii]['mc'] = myMovieClip;

      //alter 0,0 coordinate
      2dArray[0][0]['href'] = 'store other arbitrary data on grid';
      2dArray[0][0]['mc'] = myMC;

      //access row 2, col 4 MC

  7. Amazing. Dynamic variable names were one of my favorite things about actionscript 2.0 and they seem much harder to do now. This is so useful.

  8. Wow this is so useful, I’ve been trying to figure this out for days, you’ve saved me life. Really.
    Thank you 🙂

  9. Thank you very much for sharing this code. I have a question tho. How would I use this for something like the SoundChannel class?

    If I want to play each channel, I would end up doing something like this:

    channelArray[i] = soundArray[i].play;

    Which might actually assign a Sound object to channelArray.

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