<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<script type="text/javascript">
var owe=prompt("计算第一个值","");
var oee=prompt("计算第二个值","");
var oae=prompt("请输入运算符","");
var sk;
a=parseFloat(owe);
d=parseFloat(oee);
switch(oae){
case "+":
sk=a+d;
break;
case "-":
sk=a-d;
break;
case "*":
sk=a*d;
break;
case "/":
sk=a/d;
break;
}
alert("计算的数字是"+a+oae+d+"="+sk);
</script>
<body>
</body>
</html>
原文：https://www.cnblogs.com/tiantongtong/p/13084159.html