Run results for: structuredClone test

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_1_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/143.0.7499.38 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 143

Operating system: iOS 26.1.0

Device Platform: Mobile

Date tested: 9 months ago

Benchmark engine: Benchmark.js

Native map(shallow clone)

79.0M/s

Native map deep slice(turns objects into arrays)

50.0M/s

Native map deep slice at 0(turns objects into arrays)

47.6M/s

Object.assign shallow clone

45.1M/s

Recursive deep clone

6.7M/s

Map deep clone

4.1M/s

Native JSON parse

1.4M/s

Lodash cloneDeep

839K/s

structuredClone

350K/s

View exact numbers

Test name	Executions per second
✓ Native map(shallow clone)	78,954,968 Ops/sec
Native map deep slice(turns objects into arrays)	49,951,080 Ops/sec
Native map deep slice at 0(turns objects into arrays)	47,597,780 Ops/sec
Object.assign shallow clone	45,089,748 Ops/sec
Recursive deep clone	6,667,400 Ops/sec
Map deep clone	4,074,594 Ops/sec
Native JSON parse	1,400,994 Ops/sec
Lodash cloneDeep	839,058 Ops/sec
structuredClone	350,446 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 testArray = [{
  description: 'Random description.',
  testNumber: 123456789,
  testBoolean: true,
  testObject: {
    testString: 'test string',
    testNumber: 12345
  },
  testArray: [{
    myName: 'test name',
    myNumber: 123245
  }]
},{
  description: 'Random description.',
  testNumber: 123456789,
  testBoolean: true,
  testObject: {
    testString: 'test string',
    testNumber: 12345
  },
  testArray: [{
    myName: 'test name',
    myNumber: 123245
  }]
}];

var testCopy = null;

var deepClone = function(obj) {
   var out;
    if (Array.isArray(obj)) {
        out = [];
        for (var index = 0; index < obj.length; ++index) {
            let subArray = obj[index];
            out.push((subArray === null) ? subArray : (subArray instanceof Date) ? new Date(subArray.valueOf()) : (typeof subArray === 'object') ? deepClone(subArray) : subArray);
        }
    } else {
        out = {};
        for (var key in obj) {
            var subObject = obj[key];
            out[key] = subObject === null ? subObject : subObject instanceof Date ? new Date(subObject.valueOf()) : (typeof subObject === 'object') ? deepClone(subObject) : subObject;
            
           
        }
    }
    return out;
};

Tests:

Lodash cloneDeep
testCopy = _.cloneDeep(testArray);
Native map deep slice(turns objects into arrays)
testCopy = testArray.map(arr => testArray.slice());
Native JSON parse
testCopy = JSON.parse(JSON.stringify(testArray));
Native map deep slice at 0(turns objects into arrays)
testCopy = testArray.map(arr => testArray.slice(0));
Native map(shallow clone)
testCopy = testArray.map(arr => arr);
Recursive deep clone
testCopy = deepClone(testArray);
Map deep clone
testCopy = testArray.map(arr => deepClone(arr));
Object.assign shallow clone
testCopy = Object.assign([...testArray]);
structuredClone
testCopy = structuredClone(testArray);