Nodejs Utililty Methods Array Value

Array.prototype.toggleValue = function (value) {
    var index = this.indexOf(value);
    if (index === -1) {
        this.push(value);
    else {
        this.splice(index, 1);
};
...

Array.prototype.trim = function (value) {
  var array = this.slice(0); 
  while (array.length > 0 && array[0] === value) {
    array.shift();
  while (array.length > 0 && array[array.length - 1] === value) {
    array.pop();
  return array;
...

Array.prototype.tw_indexOf = function(val) {
    for (var i = 0; i < this.length; i++) {
        if (this[i] == val) return i;
    return -1;
};
Array.prototype.tw_remove = function(val) {
    var index = this.indexOf(val);
    if (index > -1) {
...

Array.prototype.unset = function (value) {
    if (this.indexOf(value) !== -1) { 
        this.splice(this.indexOf(value), 1);
};

Array.prototype.unset = function(value,isIndex) {
  var isIndex = isIndex || 0;
  if (value == undefined) {
    this.length = 0;
    return this;
  for (var i = 0, j = 0, l = this.length; i < l; ++i) {
    if (!isIndex) {
      if (this[i] != value) { 
...

Array.prototype.unset = function(value,isIndex) {
  var isIndex = isIndex || 0;
  if (value == undefined) {
    this.length = 0;
    return this;
  for (var i = 0, j = 0, l = this.length; i < l; ++i) {
    if (!isIndex) {
      if (this[i] != value) { 
...

Array.prototype.valueIndexOf = function(val) {
  for (var i = 0; i < this.length; i++) {
    if (this[i] == val) return i;
  return -1;
};

Array.prototype.valuesAt = function(indices) {
  var ary = this;
  return indices.map(function(idx) { return ary[idx] });
};

Array.asArray = function(val){
    if(Array.isArray(val)){
        return val;
    } else {
        return [val];