<p><label>請選擇一個選項：</label></p>
<p><select></p>
<p><option value="option1">選項1</option></p>
<p><option value="option2">選項2</option></p>
<p><option value="option3">選項3</option></p>
<p></select></p>

<p><label>請選擇一個選項：</label></p>
<p><select id="mySelect"></p>
<p><option value="option1">選項1</option></p>
<p><option value="option2">選項2</option></p>
<p><option value="option3">選項3</option></p>
<p></select></p>
<p><script></p>
<p>let select = document.getElementById('mySelect');</p>
<p></script></p>

<p><button onclick="addOption()">添加新選項</button></p>
<p><script></p>
<p>let select = document.getElementById('mySelect');</p>
<p>function addOption() {</p>
<p>let option = document.createElement('option');</p>
<p>option.value = 'option4';</p>
<p>option.innerHTML = '選項4';</p>
<p>select.add(option, 3);</p>
<p>}</p>
<p></script></p>

<p><button onclick="removeOption()">刪除選項2</button></p>
<p><script></p>
<p>let select = document.getElementById('mySelect');</p>
<p>function removeOption() {</p>
<p>select.remove(1);</p>
<p>}</p>
<p></script></p>

<p><label for="mySelect">當前選擇：</label></p>
<p><span id="currentOption"></span></p>
<p><script></p>
<p>let select = document.getElementById('mySelect');</p>
<p>let currentOption = document.getElementById('currentOption');</p>
<p>select.addEventListener('change', function() {</p>
<p>currentOption.innerHTML = select.value;</p>
<p>});</p>
<p></script></p>

<strike id="aussm"></strike>

<strike id="aussm"></strike>