JavaScript Array Object Implementation adds a method to return random elements _javascript tips

The example in this article describes a method for adding a random element to a JavaScript array object implementation. Share to everyone for your reference. Specifically as follows:

Core Features:

Probabilistic random, sequential random, random bubbling

This method comes from the practice of personal handwriting JavaScript, only involves JavaScript 1.5 (ECMAscript 3 international Standard) language itself, in all JS engine implementations

Add the random method for the array object:

(function () {
  function random_sn (iarray) {return
    Math.floor (Math.random () * iarray.length);
  }
  function Probability_random (iarray) {
    var random_int;
    if (iarray.random_sn = = undefined)
      iarray.random_sn =-1;
    Do random_int = RANDOM_SN (IArray);
    while (Random_int = = iarray.random_sn)
    iarray.random_sn = Random_int;
    return iarray[random_int];
  }
  function Sequence_random (iarray) {return
    Iarray.splice (RANDOM_SN (IArray), 1) [0];
  }
  Array.prototype.random = function (Mode, Pop) {
    if (! Mode) return to
      probability_random (this);
    if (! POP) {
      if (! (This. Random_queue && this. Random_queue.length)) This
        . Random_queue = [].concat (this);
      Return Sequence_random (this. random_queue);
    }
    Return Sequence_random (this);
  };
}) ();

Use examples:

"Probabilistic random"////
element return is completely random, the probability of occurrence is uncertain, and a finite number of calls does not guarantee that all elements of
var ielement = Iarray.random () can be returned;
The "sequential random"////
element return is periodic, and the elements appear once in each cycle, but the order is variable
var ielement = Iarray.random (true);
"Random bubbling"////
each call randomly extracts an element from the original array to return (the original array changes in place)
var ielement = Iarray.random (True, true);

I hope this article will help you with your JavaScript programming.