<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
function checkAll(allNode){
//找到所有的的选项
var items = document.getElementsByName("item");
//找到全选按钮的对象
//var allNode = document.getElementsByName("all")[0];
for(var i = 0 ; i<items.length ; i++){
items[i].checked = allNode.checked;
}
}
function getSum(){
var items = document.getElementsByName("item");
var sum = 0;
for(var i = 0 ; i<items.length ; i++){
if(items[i].checked){
sum += parseInt(items[i].value);
}
}
var spanNode = document.getElementById("sumid");
spanNode.innerHTML = (" ¥"+sum).fontcolor("green");
}
</script>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<body>
<div>商品列表</div>
<input type="checkbox" name="item" value="3000" />笔记本电脑3000元<br />
<input type="checkbox" name="item" value="1800" />笔记本电脑1800元<br />
<input type="checkbox" name="item" value="300" />笔记本电脑300元<br />
<input type="checkbox" name="item" value="3000" />笔记本电脑3000元<br />
<input type="checkbox" name="item" value="3000" />笔记本电脑3000元<br />
<input type="checkbox" name="item" value="3000" />笔记本电脑3000元<br />
<input type="checkbox" name="all" onclick="checkAll(this)" /> 全选<br />
<input type="button" value="总金额：" onclick="getSum()" /><span id="sumid"></span>
</body>
</html>
![实现计算器功能[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)