<!DOCTYPE html>
<html>
<head>
<meta charset="GB18030">
<title>Insert title here</title>
</head>
<body>
<script type="text/javascript">
function sum1() {
var total = 0;
var arr = document.getElementsByName("item");
for ( var i in arr) {
if (arr[i].checked) {
total += parseInt(arr[i].value);
}
};
var ssum=total+"yuan";
alert(ssum);
}
function checkall() {
var brrs = document.getElementsByName("item");
for ( var y in brrs) {
brrs[y].checked =true;
};
}
</script>
<input type="checkbox" name="item" value="4000" />笔记本电脑
: 4000
<br />
<input type="checkbox" name="item" value="4000" />笔记本电脑 4000
<br />
<input type="button" value="总金额" onclick="sum1()" /><span id="show"></span>
<input type="button" value="全选" onclick="checkall()" />
</body>
</html>
手动全选可以,但是点完全选按钮之后,在点总金额就是 NaN,怎么回事啊?
选取HTML元素最好别用for in,他会把一些DOM对象也选进去。