js insertBefore

 1     <select id="city" size="4" style="width:50px">

 2         <option id="hn">湖南</option>

 3         <option id="hb">湖北</option>

 4     </select>

 5       <script type="text/javascript">

 6           /*创建"新元素"，插入到"湖南"元素之前

 7           var newOptionElement = document.createElement("option");

 8           newOptionElement.setAttribute("id","new");

 9           newOptionElement.innerHTML = "新元素";

10           var cityElement = document.getElementById("city");

11           var hnElement = document.getElementById("hn");

12           cityElement.insertBefore(newOptionElement,hnElement);　　//新元素

13         */

14           //创建"新元素"，插入到"湖南"元素之后

15           var newOptionElement = document.createElement("option");

16           newOptionElement.setAttribute("id","new");

17           newOptionElement.innerHTML = "新元素";

18           var cityElement = document.getElementById("city");

19           var hnElement = document.getElementById("hn");

20

21             //兄弟节点  nextSibling

22             cityElement.insertBefore(newOptionElement,hnElement.nextSibling);

23      </script>

js insertBefore,布布扣,bubuko.com