<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Title</title>
<meta charset="UTF-8">
</head>
<body>
<select onchange="f3()">内容改变触发事件
<option>北京</option>
<option>上海</option>
<option>广州</option>
</select>
<script>
function f3() {
alert(123);
}
</script>
</body>
</html>
原文：https://www.cnblogs.com/startl/p/12249987.html