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deep cloning of objects (v4)

Revision 4 of this benchmark created by Marcin on July 2, 2013

Description

testing only DEEP cloning of objects

Preparation HTML

<script src="http://code.jquery.com/jquery-1.8.0.js" type="text/javascript"></script>
<script src="https://raw.github.com/bestiejs/lodash/master/lodash.min.js"></script>
<script>var lodash = _.noConflict();</script>

<script>
function deepClone1(obj) {
  return JSON.parse(JSON.stringify(obj));
}

function deepClone2(obj) {
  var i, ret, ret2;
  if (typeof obj === "object") {
    if (obj === null) return obj;
    if (Object.prototype.toString.call(obj) === "[object Array]") {
      ret = [];
      for (i = 0; i < obj.length; i++) {
        if (typeof obj[i] === "object") {
          ret2 = deepClone2(obj[i]);
        } else {
          ret2 = obj[i];
        }
        ret.push(ret2);
      }
    } else {
      ret = {};
      for (i in obj) {
        if (obj.hasOwnProperty(i)) {
          if (typeof(obj[i] === "object")) {
            ret2 = deepClone2(obj[i]);
          } else {
            ret2 = obj[i];
          }
          ret[i] = ret2;
        }
      }
    }
  } else {
    ret = obj;
  }

  return ret;
}

// comes from: http://jsperf.com/cloning-an-object/23
function deepClone3(obj) {
    var target = {};
    for (var i in obj) {
      if (typeof(obj) === 'object') {
        target[i] = deepClone3(obj[i]);
      }
      else {
        target[i] = obj[i];
      }
    }
    return target;
  }

// adapted from: http://jsperf.com/cloning-an-object/23
function deepClone4(obj) {
   return lodash.clone(obj, /*deep=*/true);
}

// adapted from: http://jsperf.com/cloning-an-object/23
function deepClone5(obj) {
   return jQuery.extend(/*deep=*/true, {}, obj);
}

// comes from: http://jsperf.com/cloning-an-object/23
function deepClone6(obj) {
   return Object.clone(obj);
}

// adapted/reduced from: http://jsperf.com/structured-clone-objects/2 and https://developer.mozilla.org/en-US/docs/DOM/The_structured_clone_algorithm
function deepClone7(oToBeCloned) {
  if (oToBeCloned === null || !(oToBeCloned instanceof Object)) { return oToBeCloned; }
  var oClone, fConstr = oToBeCloned.constructor;
  oClone = new fConstr();
  for (var sProp in oToBeCloned) { oClone[sProp] = deepClone7(oToBeCloned[sProp]); }
  return oClone;
};


// ******************

// comes from: http://jsperf.com/cloning-an-object/23
  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
    }
  });

// ******************

// ensure that the deep-clone is actually accurate
function compareObjs(obj1, obj2) {
  // snapshot how `obj1` currently looks
  var orig = JSON.stringify(obj1);

  // test if `obj2` really was a clone of `obj1`
  if (orig !== JSON.stringify(obj2)) {
    throw new Error("failed test 1");
  }

  // do some mutations to `obj2` clone
  obj2.b = "3";
  // check that `obj1` wasn't affected
  if (orig !== JSON.stringify(obj1)) {
    throw new Error("failed test 2");
  }

  obj2.c.push("foobar");
  // check that `obj1` wasn't affected
  if (orig !== JSON.stringify(obj1)) {
    throw new Error("failed test 3");
  }

  obj2.c[2].d++;
  // check that `obj1` wasn't affected
  if (orig !== JSON.stringify(obj1)) {
    throw new Error("failed test 4");
  }

  obj2.c[2].e = {
    f: "hello world"
  };
  // check that `obj1` wasn't affected
  if (orig !== JSON.stringify(obj1)) {
    throw new Error("failed test 5");
  }
}
</script>

Setup

var a = [
      {id: 1, name: {first: 'Joe', last: 'Fabiano'}, ip: '0.0.0.1', email: 'Joe.Fabiano@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'},
      {id: 2, name: {first: 'Fred', last: 'Wecler'}, ip: '0.0.0.1', email: 'Fred.Wecler@ex.com'},
      {id: 3, name: {first: 'Steve', last: 'Wilson'}, ip: '0.0.0.1', email: 'Steve.Wilson@ex.com'},
      {id: 4, name: {first: 'Maria', last: 'Fernandez'}, ip: '0.0.0.1', email: 'M.Fernandez@ex.com'},
      {id: 5, name: {first: 'Pierre', last: 'Barbault'}, ip: '0.0.0.1', email: 'Pierre.Barbault@ex.com'},
      {id: 6, name: {first: 'Nancy', last: 'Moore'}, ip: '0.0.0.1', email: 'Nancy.Moore@ex.com'},
      {id: 7, name: {first: 'Barbara', last: 'MacDonald'}, ip: '0.0.0.1', email: 'B.MacDonald@ex.com'},
      {id: 8, name: {first: 'Wilma', last: 'Williams'}, ip: '0.0.0.1', email: 'Wilma.Williams@ex.com'},
      {id: 9, name: {first: 'Sasha', last: 'Silver'}, ip: '0.0.0.1', email: 'Sasha.Silver@ex.com'},
      {id: 10, name: {first: 'Don', last: 'Pérignon'}, ip: '0.0.0.1', email: 'Don.Pérignon@ex.com'},
      {id: 11, name: {first: 'Aaron', last: 'Kinley'}, ip: '0.0.0.1', email: 'Aaron.Kinley@ex.com'}
    ];

Test runner

Ready to run.

Testing in
Test		Ops/sec
deepClone1 (JSON parse/stringify)	`compareObjs(a, deepClone1(a));`	ready
deepClone2 (full obj deep clone)	`compareObjs(a, deepClone2(a));`	ready
deepClone3 (simple for-in)	`// comes from: http://jsperf.com/cloning-an-object/23 // NOTE: this jsperf is intentionally set up to prove that the // deep cloning shown on that other jsperf is invalid, that's // why this test throws an error, because the comparison fails. compareObjs(a, deepClone3(a));`	ready
deepClone4 (lodash deep clone)	`// adapted from: http://jsperf.com/cloning-an-object/23 compareObjs(a, deepClone4(a));`	ready
deepClone5 (jQuery deep extend)	`// adapted from: http://jsperf.com/cloning-an-object/23 compareObjs(a, deepClone5(a));`	ready
deepClone6 (Object.clone)	`// comes from: http://jsperf.com/cloning-an-object/23 // NOTE: this jsperf is intentionally set up to prove that the // deep cloning shown on that other jsperf is invalid, that's // why this test throws an error, because the comparison fails. compareObjs(a, deepClone6(a));`	ready
deepClone7 (structured clone)	`// adapted/reduced from: http://jsperf.com/structured-clone-objects/2 // and https://developer.mozilla.org/en-US/docs/DOM/The_structured_clone_algorithm compareObjs(a, deepClone7(a));`	ready

Revisions

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

Revision 1: published by Kyle Simpson on September 11, 2012
Revision 2: published by Bernie on June 11, 2013
Revision 3: published by derry on July 1, 2013
Revision 4: published by Marcin on July 2, 2013
Revision 5: published by Marcin on July 2, 2013
Revision 9: published by Oscar Campbell on June 18, 2014
Revision 10: published by Oscar Campbell on June 19, 2014
Revision 11: published on June 19, 2014
Revision 12: published by Oscar Campbell on June 22, 2014
Revision 28: published by cari bisnis rumahan sampingan on February 6, 2015
Revision 29: published by cari modal usaha on February 9, 2015
Revision 31: published on June 8, 2015