<html>
<head>
</head>
<script>
//保留几位小数
function fmoney(obj, num) {
return obj.value = formatNumber(obj.value, 2, 1);
}
/*
将数值四舍五入后格式化.
@param num 数值(Number或者string)
@param cent 要保留的小数位(Number)
@param isThousand 是否须要千分位 0:不须要,1:须要(数值类型);
@return 格式的字符串,如'1,234,567.45'
@type String
*/
function formatNumber(num, cent, isThousand) {
num = num.toString().replace(/$|\,/g, '');
if (isNaN(num))//检查传入数值为数值类型.
num = "0";
if (isNaN(cent))//确保传入小数位为数值型数值.
cent = 0;
cent = parseInt(cent);
cent = Math.abs(cent);//求出小数位数,确保为正整数.
if (isNaN(isThousand))//确保传入是否须要千分位为数值类型.
isThousand = 0;
isThousand = parseInt(isThousand);
if (isThousand < 0)
isThousand = 0;
if (isThousand >= 1) //确保传入的数值仅仅为0或1
isThousand = 1;
sign = (num == (num = Math.abs(num)));//获取符号(正/负数)
//Math.floor:返回小于等于其数值參数的最大整数
num = Math.floor(num * Math.pow(10, cent) + 0.50000000001);//把指定的小数位先转换成整数.多余的小数位四舍五入.
cents = num % Math.pow(10, cent); //求出小数位数值.
num = Math.floor(num / Math.pow(10, cent)).toString();//求出整数位数值.
cents = cents.toString();//把小数位转换成字符串,以便求小数位长度.
while (cents.length < cent) {//补足小数位到指定的位数.
cents = "0" + cents;
}
if (isThousand == 0) //不须要千分位符.
return (((sign) ? '' : '-') + num + '.' + cents);
//对整数部分进行千分位格式化.
for (var i = 0; i < Math.floor((num.length - (1 + i)) / 3); i++)
num = num.substring(0, num.length - (4 * i + 3)) + ','
+ num.substring(num.length - (4 * i + 3));
return (((sign) ?
'' : '-') + num + '.' + cents);
}
</script>
<input onblur="fmoney(this,2);" value="" />
<body>
</body>
</html>