js 擷取 select的option的 id值

<select >
<option value="">--請選擇--</option>

<option id="1" value="1">--1--</option>

<option id="2" value="2">--2--</option>
</select>
           

js

var selectIndex =document.getElementById("usertype").selectedIndex;
          var activeName_value =document.getElementById("usertype").options[selectIndex].id;
          alert(activeName_value);
           

jquery

$("#usertype option:selected").text()
$("#usertype").find("option:selected").text()