<meta charset="utf-8">
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<select onchange="func()">
<?php for($i=0;$i<4;$i++){?>
  <option value="<?php echo $i?>">选择<?php echo $i;?></option>
<?php }?>
</select>
<script type="text/javascript">
	function func(){
 //获取被选中的option标签
 var vs = $(‘select option:selected‘).val();
 alert(vs);
}
</script>
原文:https://www.cnblogs.com/ayanboke/p/11508049.html