Loop through layers and determine if its a text containing layer

Question

Hi,
I am trying to loop/iterate through all layers, determine if it's a "text-layer", if it is, set it's opacity to 0.
This is what I have so far:
var iapp = new Illustrator.Application();
var openoptions = new Illustrator.OpenOptions();
var idoc = iapp.Open("c:\\myFile.pdf", Illustrator.AiDocumentColorSpace.aiDocumentRGBColor, openoptions);
Illustrator.Layer mainlayer = idoc.Layers["Layer 1"];
foreach (Illustrator.GroupItem groupitem in idoc.GroupItems)
foreach (Illustrator.GroupItem item in groupitem.GroupItems)
/* determine here if its a textlayer */
if( ... ) // (item.TextFrames.Count > 0) perhaps?
item.Opacity = 0;
//item.Opacity = 15; //this indeed sets the layer opacity 15

Answer 1

Is that VB? Does your soloution need to be too?
#target illustrator
textLayersOff();
function textLayersOff() {
          var doc = app.activeDocument;
          for ( var i = 0; i < doc.layers.length; i++ ) {
                    if ( doc.layers[i].textFrames.length > 0 ) { doc.layers[i].opacity = 0; };
This would check for text frames NOT their content… if any