<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
.panel {
border: 4px solid #ccc;
width: 202px;
margin: 50px auto;
}
.panel p,.panel input{
font-family: "黑体";
font-size:20px;
margin:5px;
float:left;
}
.panel p{
border:4px solid #ddd;
height:30px;
width:123px;
padding:5px;
}
.panel input{
height:40px;
width:40px;
}
</style>
<script type="text/javascript">
function cal(e) {
var obj = e.target || e.srcElement;
if(obj.nodeName != "INPUT") {
return;
}
var value = obj.value;
var screen = document.getElementById("screen");
if(value=="C") {
screen.innerHTML = "";
} else if (value=="=") {
var exp = screen.innerHTML;
try {
var r = eval("("+exp+")");
screen.innerHTML = r;
} catch(e) {
console.log(e);
screen.innerHTML = "Error";
}
} else {
screen.innerHTML += value;
}
}
</script>
</head>
<body>
<div class="panel" onclick="cal(event);">
<div>
<p id="screen"></p>
<input type="button" value="C">
<div style="clear:both"></div>
</div>
<div>
<input type="button" value="7">
<input type="button" value="8">
<input type="button" value="9">
<input type="button" value="/">
<input type="button" value="4">
<input type="button" value="5">
<input type="button" value="6">
<input type="button" value="*">
<input type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<input type="button" value="-">
<input type="button" value="0">
<input type="button" value=".">
<input type="button" value="=">
<input type="button" value="+">
<div style="clear:both"></div>
</div>
</div>
</body>
</html>