Nodejs Utililty Methods Array Random

Array.prototype.rand = function() {
  return this[Math.floor(Math.random() * this.length)];
};

Array.prototype.randEl = function () {
  return this[Math.floor(Math.random() * this.length)]
};

Array.prototype.randFromArr = function() {
  var a = this[Math.floor(Math.random() * this.length)]
  return a
};

Array.prototype.random = function() {
  return this[Math.floor( Math.random() * this.length )]

Array.prototype.random = function() {
  return this[Math.floor(Math.random() * this.length)];
};

Array.prototype.random = function() {
    return this[~~(this.length * Math.random())];
};
function rand(n) {
    return ~~(Math.random() * n);

Math.randomInt = function (min, max) {
    return Math.floor(Math.random() * (max - min +1)) + min
};
Array.prototype.random = function () {
   return this[Math.randomInt(0, this.length-1)];

Array.prototype.random = function() {
  if (!this.length) return;
  return this[Math.floor(Math.random() * this.length)];
};

Array.prototype.random = function () {
  return this[Math.floor((Math.random()*this.length))];
};

Array.prototype.random = function() {
    if (Object.prototype.toString.call(this) !== '[object Array]') {
        throw new TypeError("`this` must be Array, not " + typeof this);
    return this[Math.floor(Math.random() * this.length)];
};