Cloning an Object (v109)

Revision 109 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 = {"mirror-char|rahc-rorrim":{"from":["c","d"],"do":["c","0","c","1","c","2","c","3","c","4","c","5","c","6","c","7","7","|",["3",["6",["4",["0",["1","t","2","1","t","2"],"0"],"4"],"|",["5",["4",["2",["0","|",["1","|","1"],"|","0"],"2"],"|",["2","|",["1","|",["0","|","0"],"|","1"],"|","2"],"|","4"],"5"],"|","6"],"3"],"|","7","7","d","6","d","5","d","4","d","3","d","2","d","1","d","0","d"],"to":["c","d"]},"str|len":{"from":["s","count"],"do":["s",["s","temp","s","temp","s","temp","s","temp","s","temp","s","temp","s","temp","s","temp","count",{"call":"str|len","args":["s","count"]},"|","count","temp","s","temp","s","temp","s","temp","s","temp","s","temp","s","temp","s","temp","s"],"s"],"to":["s","count"]},"revloop|poolver":{"from":["in","count","out"],"do":["count",["in",[{"call":"mirror-char|rahc-rorrim","args":["in","out"]}],"out",{"call":"revloop|poolver","args":["in","count","out"]}],"count"],"to":["in","count","out"]},"reverse|esrever":{"from":["in","out"],"do":[{"call":"str|len","args":["in","count"]},{"call":"revloop|poolver","args":["in","count","out"]},{"call":"nel|rts","args":["count","out"]}],"to":["in","out"]},"main":{"from":["in"],"do":[{"call":"reverse|esrever","args":["in","out"]}],"to":["out"]}}
  
  
  function clone(obj) {
   var target = {};
   for (var i in obj) {
    if (obj.hasOwnProperty(i)) {
     target[i] = obj[i];
    }
   }
   return target;
  }
  
  Object.defineProperties(Object, {
   'extend': {
    'configurable': true,
    'enumerable': false,
    'value': function extend(what, wit) {
     var extObj, witKeys = Object.keys(wit);
  
     extObj = Object.keys(what).length ? Object.clone(what) : {};
  
     witKeys.forEach(function(key) {
      Object.defineProperty(extObj, key, Object.getOwnPropertyDescriptor(wit, key));
     });
  
     return extObj;
    },
    'writable': true
   },
   'clone': {
    'configurable': true,
    'enumerable': false,
    'value': function clone(obj) {
     return Object.extend({}, obj);
    },
    'writable': true
   }
  });
</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
JQuery.extend
var newObject = jQuery.extend({}, oldObject);
ready
simple clone function
var newObject = clone(oldObject);
ready
ES5 Object.clone
var newObject = Object.clone(oldObject);
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.