Nodejs Utililty Methods Number Calculate

Number.prototype.randStr = function() {
    var alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    var res = '';
    for(var i = 0; i < this; i++) {
        res += alpha[Math.floor(Math.random() * alpha.length)];
    return res;

Number.prototype.range  = function (a, b, i) {
    i = i || true;
    var min = Math.min.apply(Math, [a, b]),
        max = Math.max.apply(Math, [a, b]);
    return i ? this >= min && this <= max : this > min && this < max;
};

Number.prototype.repeat = function(n){
  return this.toString().repeat(n);

Number.prototype.repr = function () {
    var digits = (arguments.length > 0)? arguments[0] : undefined;
    if (typeof digits !== "number") {
        return Number(this);
    if (digits <= 0) {
        return Math.round(this);
    var factor = Math.pow(10, digits);
...

Number.prototype.reprLocale = function () {
    var result,
        digits = (arguments.length > 0)? arguments[0] : undefined,
        number = String(this.repr(digits)),
        int = number.split(".")[0],
        intparts = [],
        float = (number.indexOf(".") >= 0)? number.split(".")[1] : undefined;
    while (int.length > 0) {
        if (int.length <= 3) {
...

Number.prototype.reverse = function() {
  return parseInt(this.toString().split('').reverse().join(''), 10);

Number.prototype.rnd2 = function () {
  return Math.round(this.valueOf() * 100) / 100;

Number.prototype.rotate = Number.prototype.rotate || function () {
  return Math.floor((this / 10) + ((this % 10) * Math.pow(10, exports.digitLength(this) - 1)));
};

Number.prototype.safeDivideBy = function(x) {
    var result = this.valueOf() / x;
    if(result === Infinity) {
        return 0;
    else {
        return result;

Number.prototype.send = function(method) {
  return this[method].call();
};