Javascript:如何将所有选项从一个选择元素复制到另一个元素？

Question

我怎么能复制所有options一select元到另一个？请给我最简单的方法,我对循环过敏.

请帮我.提前致谢!

Answer 1

没有循环的最简单方法之一是使用jquery(select1= select 1的select2id ,= select 2的id):

$('#select1 option').clone().appendTo('#select2');

没有jquery:

var select1 = document.getElementById("select1");
var select2 = document.getElementById("select2");
select2.innerHTML = select2.innerHTML+select1.innerHTML;

Answer 2

HTML:

<select id="selector_a">
    <option>op 1</option>
    <option>op 2</option>
</select>

<select id="selector_b">
    <option>op 3</option>
    <option>op 4</option>
</select>

JavaScript的:

var first = document.getElementById('selector_a');
var options = first.innerHTML;

var second = document.getElementById('selector_b');
var options = second.innerHTML + options;

second.innerHTML = options;