Run results for: Lodash cloneDeep vs deepFreeze vs deepClone vs JSON.parse(JSON.stringify())

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 YaBrowser/25.6.0.0 Safari/537.36

Browser: Yandex Browser 25

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

custom deepClone()

2.1M/s

custom deepFreeze()

1.3M/s

JSON

602K/s

Lodash cloneDeep

305K/s

View exact numbers

Test name	Executions per second
✓ custom deepClone()	2,087,775 Ops/sec
custom deepFreeze()	1,304,007 Ops/sec
JSON	601,803 Ops/sec
Lodash cloneDeep	304,689 Ops/sec

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var MyObject = {
  description: 'Creates a deep copy of source, which should be an object or an array.',
  myNumber: 123456789,
  myBoolean: true,
  array: [1,2,3,4,5,6,7,8,9,0],
  nestedObject: {
  	a: [{x: 1}, {x: 1}, {x: 1}],
    b: [{x: 1}, {x: 1}, {x: 1}],
    c: [{x: 1}, {x: 1}, {x: 1}]
  },
  jayson: {
    stringify: 'JSON.stringify() method converts a JavaScript value to a JSON string....',
    parse: 'JSON.parse() method parses a JSON string...'
  }
};

var myCopy = null;

function deepFreeze(x) {

  if (!x || typeof x !== 'object') {
  	return x;
  }
  
  if (Array.isArray(x)) {
  	const y = [];
    for (let i = 0; i < x.length; i++) {
      y.push(deepFreeze(x[i]));
    }
    return Object.freeze(y);
  }
  
  const y = {};
  
  for (const key in x) {
  	if (x.hasOwnProperty(key)) {
      y[key] = deepFreeze(x[key]);
    }
  }
  
  return Object.freeze(y);
  
}

function deepClone(x) {

  if (!x || typeof x !== 'object') {
    return x;
  }

  if (Array.isArray(x)) {
    const y = [];
    for (let i = 0; i < x.length; i++) {
      y.push(deepClone(x[i]));
    }
    return y;
  }

  const y = {};
  for (const key in x) {
  	if (x.hasOwnProperty(key)) {
      y[key] = deepClone(x[key]);   
    }
  }

  return y;

}

Tests:

Lodash cloneDeep
myCopy = _.cloneDeep(MyObject);
custom deepFreeze()
myCopy = deepFreeze(MyObject)
custom deepClone()
myCopy = deepClone(MyObject);
JSON
myCopy = JSON.parse(JSON.stringify(MyObject));