Equivalent to PHP function number_format in Javascript

number_format.js

function number_format(number, decimals, dec_point, thousands_point) {

    if (number == null || !isFinite(number)) {
        throw new TypeError("number is not valid");
    }

    if (!decimals) {
        var len = number.toString().split('.').length;
        decimals = len > 1 ? len : 0;
    }

    if (!dec_point) {
        dec_point = '.';
    }

    if (!thousands_point) {
        thousands_point = ',';
    }

    number = parseFloat(number).toFixed(decimals);

    number = number.replace(".", dec_point);

    var splitNum = number.split(dec_point);
    splitNum[0] = splitNum[0].replace(/\B(?=(\d{3})+(?!\d))/g, thousands_point);
    number = splitNum.join(dec_point);

    return number;
}