append-select2.js

<select id="ddlModules" class="select2"></select>
populateSelect2("ddlModules", null, "");


function populateSelect2(elemId, data, selectedValue) {

    var $select = $("#" + elemId);

    $.each(data, function (ix, obj) {
        var itemSelected = false;
        if (isObjValid(selectedValue)) {
            itemSelected = (selectedValue === obj.id);
        }
        var newOption = new Option(obj.text, obj.id, false, itemSelected);
        $select.append(newOption);
    });

    if (!isObjValid(selectedValue) && !isInputRequired($select)) {
        $select.val(null);
    }

    $select.trigger("change");
}

function isObjValid(obj) {

    if (typeof (obj) === "undefined" || obj === null) { return false; }
    return true;

}