<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>javascript 的calc</title>
</head>
<body> <center >
<form action="" id='meform'>
<input type="text" name='num1'><br>
<input type="button" value="-" onclick="do1('-')">
<input type="button" value="+" onclick="do1('+')">
<input type="button" value="*" onclick="do1('*')">
<input type="button" value="/" onclick="do1('/')"><br>
<input type="text" name='num2'>
<br>计算的结果是：<h2 id="we"></h2>
</form></center>
<script>
function do1(oper){
var num1 = parseFloat(document.getElementById('meform').num1.value)
var num2 =parseFloat(document.getElementById('meform').num2.value)
switch(oper){
case '+':
var res=num1+num2;
break;
case '-':
var res=num1-num2;
break;
case '*':
var res=num1*num2;
break;
case '/':
var res=num1/num2;
break;
}
document.getElementById('we').innerHTML = res;
}
</script>
</body>
</html>
有些地方是我测试获取值的方法，所以，有些代码或者函数可能有些冗余、没有使用简单的函数
