Add Multiple Item in Radcombobox using jquery

Introduction

To bind Telerik RadComboBox in Telerik Website, give only one item. But, here, I am adding multiple items in RadComboBox Using Jquery.

First, I am binding Rccolname at server side and OnClientDropDownClosed I am binding other RadCombobox.

So, first, I create a function rccolname on this get index of Rccolname combo and set this is as rccoltype Combo.

After that, on this get selected value, I have switch case condition in every case I inserted value in the array. After that, I have inserted Item in Rcombooperator using For loop.

---

 function rccolnameChange(sender, args) {
         var item = args._domEvent.target.innerText
         var index = sender._selectedIndex;
         var rccoltyp = $find("<%= rcColType.ClientID %>");
         rccoltyp._selectedIndex = index; //set index of RcColtype Conmbo
         var rccol = $find("<%= rcColType.ClientID %>");
         var name = rccol._childListElement.childNodes[index].innerText;// Get Selected Index Text
            
           if (index != 0) {
               var selectitem = new Array();
                switch (name.toLowerCase()) {
                    case 'datetime': case 'system.datetime':
                        selectitem.push("=");
                        selectitem.push(">");
                        selectitem.push("<");
                        selectitem.push("<=");
                        selectitem.push(">=");
                        selectitem.push("<>");
                        selectitem.push("IS NULL");
                        selectitem.push("IS NOT NULL");
                        selectitem.push("BETWEEN");
                        break;
                    case 'numeric': case 'decimal':
                        selectitem.push("=");
                        selectitem.push(">");
                        selectitem.push("<");
                        selectitem.push("<=");
                        selectitem.push(">=");
                        selectitem.push("<>");
                        selectitem.push("IS NULL");
                        selectitem.push("IS NOT NULL");
                        selectitem.push("Browse");
                        break;
                    case 'varchar': case 'string': case 'system.string': case 'char':
                        selectitem.push("=");
                        selectitem.push("<>");
                        selectitem.push("IS NULL");
                        selectitem.push("IS NOT NULL");
                        selectitem.push("End With");
                        selectitem.push("contains");
                        selectitem.push("Browse");
                        break;
                }

                var combo = $find("<%= RComboOperator.ClientID %>");
                combo.clearItems();
                var length = selectitem.length
                for (i = 0; i < selectitem.length; i++) {
                    var comboItem = new Telerik.Web.UI.RadComboBoxItem();
                    
                    comboItem.set_text(selectitem[i]);
                    combo.trackChanges();
                    combo.get_items().add(comboItem);
                    combo.commitChanges();
                    comboItem.select();
                }
            }
        }