<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<input type="text" name="" id="">
<button>价格查询</button>
</body>
</html>
<script>
function $(name) {
return document.getElementsByTagName(name);
}
var txt=$('input')[0];
var btn=$('button')[0];
btn.onclick=function () {
var val=txt.value;
switch(val){
case '苹果':
alert('苹果的价格是:5元');
break;
case '香蕉':
alert('香蕉的价格是:5元');
break;
case '大白菜':
alert('白菜的价格是:5元');
break;
case '土豆':
alert('土豆的价格是:5元');
break;
default:
alert('没货啦');
}
}
</script>