<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>計算器</title>
<style>
.box {
width: 180px;
padding: 15px;
background-color: #adadad;
}
.box input[type='button'] {
width: 46.5px;
height: 36px;
line-height: 36px;
text-align: center;
margin: 5px;
outline: none;
border-radius: 4px;
font-size: 14px;
}
#equ {
width: 94%;
}
#num {
width: 94%;
height: 32px;
border-radius: 4px;
margin-bottom: 15px;
padding-left: 10px;
}
</style>
</head>
<body>
<div class="box">
<input type="text" id="num">
<input type="button" value="1" onclick="count(this.value)">
<input type="button" value="2" onclick="count(this.value)">
<input type="button" value="3" onclick="count(this.value)">
<input type="button" value="4" onclick="count(this.value)">
<input type="button" value="5" onclick="count(this.value)">
<input type="button" value="6" onclick="count(this.value)">
<input type="button" value="7" onclick="count(this.value)">
<input type="button" value="8" onclick="count(this.value)">
<input type="button" value="9" onclick="count(this.value)">
<input type="button" value="0" onclick="count(this.value)">
<input type="button" value="C" onclick="count(this.value)">
<input type="button" value="+" onclick="count(this.value)">
<input type="button" value="-" onclick="count(this.value)">
<input type="button" value="*" onclick="count(this.value)">
<input type="button" value="/" onclick="count(this.value)">
<input type="button" value="(" onclick="count(this.value)">
<input type="button" value=")" onclick="count(this.value)">
<input type="button" value="." onclick="count(this.value)">
<input type="button" value="=" id="equ" onclick="count(this.value)">
</div>
</body>
</html>
<script>
function count(val) {
var num = document.getElementById('num');
switch (val) {
case 'C':
num.value = ''
break;
case '=':
num.value = eval(num.value) || '';
break;
default:
num.value = num.value + val;
break;
}
}
</script>
