js小功能

//格式化金额

function formatNum(number) {
    if (typeof number!='string') {
        number = number.toString();
    }
    number = number.replace(/\,/g, "");
    if(isNaN(number) || number == "")return "";
    number = Math.round(number * 100) / 100;
    if (number < 0)
        return '-' + outputdollars(Math.floor(Math.abs(number) - 0) + '') + outputcents(Math.abs(number) - 0);
    else
        return outputdollars(Math.floor(number - 0) + '') + outputcents(number - 0);
}
function outputdollars(number) {
    if (number.length <= 3)
        return (number == '' ? '0' : number);
    else {
        var mod = number.length % 3;
        var output = (mod == 0 ? '' : (number.substring(0, mod)));
        for (i = 0; i < Math.floor(number.length / 3); i++) {
            if ((mod == 0) && (i == 0))
                output += number.substring(mod + 3 * i, mod + 3 * i + 3);
            else
                output += ',' + number.substring(mod + 3 * i, mod + 3 * i + 3);
        }
        return (output);
    }
}
function outputcents(amount) {
    amount = Math.round(((amount) - Math.floor(amount)) * 100);
    return (amount < 10 ? '.0' + amount : '.' + amount);
}