Can't get a comparison between a folder name and a string to work

Question

Dear community,
I have a really simple ExtendScript-example that I just can't get to work and I have no idea what could be wrong. I'm trying to write a script that goes through all the items in the project panel and stores references to all the folders which names are like "layer1", "layer2", and so on, in an array. This is the code that should alert 3 times in my case, but it doesn't alert once..
for (var i=1; i<=app.project.numItems; i++)
    if ((app.project.item(i) instanceof FolderItem) && (app.project.item(i).name == "layer"+i))
        alert("found folder = " + app.project.item(i).name);
Inside the project in the root-directory there are 2 comps and 3 folders named 'layer1', 'layer2' and 'layer3' - so I should see 3 alerts when executing the above script. For testing-purposes I changed the second part of the if-statement to a 'static' value like so:
.. && (app.project.item(i).name == "layer1"))  --> then it works! But I need a dynamic solution..
Thanks very much for ANY help in advance!
Greetings,
Gilbert

Answer 1

I just tried the code and it only alerted once for me. The issue with your code is that it requires the "Layer" named folders to always be the first x items in the project file. So what is happening for you is that...
If any item appears before the first "Layer" folder then you are effectively comparing random names to each other that will never match.
ItemSomethingElse
RandomFolder                 == Layer1     (false)
Layer1                              == Layer2     (false)
Layer2                              == Layer3     (false)
Layer3                              == Layer4     (false)
Layer4                              == Layer5     (false)
ItemSomethingElse
What you need to do to keep it dynamic:
1) Gather instances of all the folders in your project into an array.
2) Loop through that array checking for indexOf "Layer".
3) If there is a match...
4) Compare that name in another loop. You'll have to determine the max number to loop through for your search, like 25 or 50 or something that won't loop forever.
5) If a Layer# match is found then run your alert.
ItemSomethingElse
RandomFolder                 indexOf("Layer")     (false, do not add)
Layer1                              indexOf("Layer")     (true, add instance to folderArray)
Layer2                              indexOf("Layer")     (true, add instance to folderArray)
Layer3                              indexOf("Layer")     (true, add instance to folderArray)
Layer4                              indexOf("Layer")     (true, add instance to folderArray)
ItemSomethingElse
So something like this should work:
var folderArray = new Array();
//Loop through project grabbing folders with layer in the name
for (var i=1; i<=app.project.numItems; i++){
     var curItem = app.project.item(i);
     if(curItem instanceof FolderItem && curItem.name.indexOf("layer") != (-1)){
          folderArray[folderArray.length] = curItem;
//Set cap for number appended to "layer"
var cap = 25;
var curName;
var folderArrayLength = folderArray.length;
//Loop through new "layer" array
for(var l=0; l<folderArrayLength; l++){
     for(var c=1; c<cap; c++){
          //Dynamic name
          curName = "layer"+c.toString();
          //Current folder name
          folderName = folderArray[l].name;
          //Compare them, alert if the match
          if(folderName == curName){
               alert("found folder = " + folderArray[l].name);
               break;//End comparison once found