Cloning an Object (v58)

Revision 58 of this benchmark created on

Description

There is no quick and easy facility for cloning an object, Some people recommend using JQuery.extend others JSON.parse/stringify

http://stackoverflow.com/questions/122102/what-is-the-most-efficient-way-to-clone-a-javascript-object

If you want the fastest possible clone function. I would personally anticipate the data structure of your object and write a custom clone to handle it.

Preparation HTML

<script src="http://code.jquery.com/jquery-1.5.1.js" type="text/javascript">
</script>
<script>
  var oldObject = {
    a: 1,
    b: 2,
    c: 3,
    d: 4,
    e: 5,
    g: {
      a: [7, 8, 9, 54.6435, 354, 353, 453.4, 534, 53.4, 5.34, 52.4, 234, 6, 678, 76.84, 53, 73, 54.2, 57, 45, 3, 67, 78, 7265, 7, 546, 37, 8, 6, 8, 436.4, 64.3, 6, 8, 7, 6, 74.7, 3634.636, 43.6, 567.8735, 3675, 7346, 834, 737643, 6, 7436, 57, 47, 57.46, 57, 46, 74.6, 7, 56.7, 26.3, 67.7, 5474.5745, 754, 754, 745, 7],
      b: [354, 35, 1, 312, 32.4, 35, 7, 76878.8, 686.7, 78.98, 77, 46.3, 3452, 13, 435, 4, 86.7, 987.89, 86775.6, 4565, 88.9, 9, 6, 75678, 9, 9067, 46, 356.65, 8.95, 246.5, 87, 678, 465.6, 86.8, 63, 56, 867.86, 43, 65.67, 586.85, 734, 77, 867, 43, 6, 67, 67.864757, 86, 8, 3.62, 5, 6, 767, 9878.85, 4.6, 867, 7436, 7, 4, 721, 5, 765, 8, 6, 3245, 7548, 53.67, 437.6],
      c: [7, 8, 9, 54.6435, 354, 353, 453.4, 534, 53.4, 5.34, 52.4, 234, 6, 678, 76.84, 53, 73, 54.2, 57, 45, 3, 67, 78, 726.5, 7, 54.6, 37, 8, 6, 8, 436.4, 64.3, 6, 8, 7, 6, 74.7, 3634.636, 43.6, 567.86735, 3675, 734.6, 834, 737.643, 6, 74.36, 57, 47, 57.46, 57, 46, 74.6, 7, 56.7, 26.3, 67.7, 5474.5745, 754, 754, 74.5, 7]
    }
  };


  var object_create = Object.create;
  if (typeof object_create !== 'function') {
    object_create = function(o) {
      function F() {}
      F.prototype = o;
      return new F();
    };
  }

  function deepCopy(src) {
    if (src === null || typeof(src) !== 'object') {
      return src;
    }

    //Honor native/custom clone methods
    if (typeof src.clone === 'function') {
      return src.clone(true);
    }

    //Special cases:
    //Date
    if (src instanceof Date) {
      return new Date(src.getTime());
    }
    //RegExp
    if (src instanceof RegExp) {
      return new RegExp(src);
    }
    //DOM Elements
    if (src.nodeType && typeof src.cloneNode === 'function') {
      return src.cloneNode(deep);
    }

    var proto = (Object.getPrototypeOf ? Object.getPrototypeOf(src) : src.__proto__);
    if (!proto) {
      proto = src.constructor.prototype;
    }
    var ret = object_create(proto);

    for (var key in src) {
      ret[key] = deepCopy(src[key]);
    }
    return ret;
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
JQuery.extend deep
var newObject = jQuery.extend(true, {}, oldObject);
ready
JSON
var newObject = JSON.parse(JSON.stringify(oldObject));
ready

Revisions

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