You are confusing arrays with objects which are different things in Javascript.  Objects do not have a length property which is why you are having issues.  To loop through an object you use a different for loop:

for (var prop in obj) {
  alert(prop + " = " + obj[prop]);
}

http://stackoverflow.com/questions/921789/how-to-loop-through-javascript-object-literal-with-objects-as-members

Cheers,

Lloyd

On Wed, Apr 23, 2014 at 3:49 PM, Phil Bearman <phil@philbearman.co.uk> wrote:

Hi David, thanks for the reply.  Yes, it's populating the array as expected.  Here's a better example script.  This is a simplified version of the actual script I'm using, but demonstrates the problem if you run it in ExtendScript Toolkit (it should pop up an alert box giving the length of the array but instead says ''undefined').

//~ Declare array (which will be populated with objects) 

var textLineObjectArray = {};

var textLine="Sample";

//~ Split string into array of characters

var textLineArray = textLine.split('');

//~ Iterate through array and for each character, create an object 

 for (var i = 0; i < textLineArray.length; i++){

     //~ Add  character name to object

        textLineObjectArray[i]={name:textLineArray[i]}

 }

//~ output length of array of objects

alert(textLine1ObjectArray.length);

Can you see any problems with this?

Phil

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On 23 April 2014 18:39, David Torno <torno@sydefxink.com> wrote:

You should still be able to get the length of the array using length. Object or item based. I would verify that the array keys (.width and .height) are actually populated correctly within the array. I usually make my object arrays a little different and more literal like this. Not that it's right or wrong, just different option.

for(var i=0; i<aryLen; i++){

     myObjectAry.push({'width': ary.width, 'height': ary.height});

}

David Torno

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On Apr 23, 2014, at 9:29 AM, Phil Bearman <phil@philbearman.co.uk> wrote:

Hi all, 

I'm doing some scripting in AE, and need to iterate through an Array of Objects, so need to find out the number of items in the array in order to set up the loop.

I had expected to be able to get the number of items using myArray.length, but this gives an 'undefined' error in ExtendScript.

The array has been populated with a loop in the following manner:

for (var i=0; i < myWidthValues.length; i++)

{

myArray[i].width=myWidthValues[i];

myArray[i].height=myHeightValues[i];

}

(this isn't the real code, just a simplified example)

And the array is functioning as expected (so for example myArray[2].width gives the result I expect).

Is there a reason that an Array of Objects won't return a 'length' value?

(I know this question would be better suited to a general javascript forum, but I've trawled internet forums to no avail, and thought I'd ask here first in case it's a quirk specific to ExtendScript).

Any help much appreciated!

Phil

--

Phil Bearman

Phil Bearman Creative Media Solutions
Motion Graphics Design

www.PhilBearman.co.uk : Nightclub & Bar ~ Production, Corporate & Events ~ DVD Products 

0161 236 2581 - 9am-5pm, Monday-Friday