How to programmatically get the list of selected layers?

// Count Selected Layers - by jazz-y
// Notes: * The content of selected layer groups may also be included
//        * Depending on whether cmd or shift selected groups or select all layers menu command
//        * Selected layers will not be lost and will remain highlighted
s2t = stringIDToTypeID;
(r = new ActionReference).putProperty(s2t('property'), p = s2t('targetLayers'));
r.putEnumerated (s2t ('document'), s2t ('ordinal'), s2t ('targetEnum'));
n =  executeActionGet (r).hasKey(p) ?  executeActionGet (r).getList(p).count : 0;
alert(n)

// Count Selected Layers - by Charu Rajput
// Notes: Selected layers will be lost

var doc = app.activeDocument;
var layers = doc.layers;

function getSelectedLayers() {
    var resultLayers = new Array();
    try {
        var idGrp = stringIDToTypeID("groupLayersEvent");
        var descGrp = new ActionDescriptor();
        var refGrp = new ActionReference();
        refGrp.putEnumerated(charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt"));
        descGrp.putReference(charIDToTypeID("null"), refGrp);
        executeAction(idGrp, descGrp, DialogModes.NO);
        for (var i = 0; i < app.activeDocument.activeLayer.layers.length; i++) {
            resultLayers.push(app.activeDocument.activeLayer.layers[i])
        }
        var id8 = charIDToTypeID("slct");
        var desc5 = new ActionDescriptor();
        var id9 = charIDToTypeID("null");
        var ref2 = new ActionReference();
        var id10 = charIDToTypeID("HstS");
        var id11 = charIDToTypeID("Ordn");
        var id12 = charIDToTypeID("Prvs");
        ref2.putEnumerated(id10, id11, id12);
        desc5.putReference(id9, ref2);
        executeAction(id8, desc5, DialogModes.NO);
        return resultLayers;
    } catch (e) {
        alert("No Layer selected or locked layer selected");
        return resultLayers;
    }
}
var selectedLayers = getSelectedLayers();
alert(selectedLayers.length);