请老师检查下代码

来源：4-3 编程练习

慕仙0287733

2020-04-24 21:44:21

<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8" />
<title>什么可以做返回值</title>
</head>
<body>
<div>
<p>请选择菜单:
<select id="menu">
<option>请选择</option>
<option value="fruit" id="fruit">水果</option>
<option value="cake" id="cake">蛋糕</option>
<option value="nut" id="nut">坚果</option>
</select></p>
<p>该系列有: <span></span></p>
</div>
<script type="text/javascript">
var select = document.getElementById('menu');
var fruit = document.getElementById('fruit');
var cake = document.getElementById('cake');
var nut = document.getElementById('nut');
var span = document.getElementsByTagName('span')[0];
select.addEventListener('change',function () {
switch (this.value) {
case 'fruit':
span.innerHTML = '苹果,香蕉,鸭梨,橙子,西瓜';
break;
case 'cake':
span.innerHTML = '慕斯,奶酪,海绵,重油,戚风';
break;
case 'nut':
span.innerHTML = '碧根果,巴旦木,夏威夷果,腰果,开心果';
break;
default:
span.innerHTML = '';
}
})
</script>
</body>
</html>