Run results for: JS Object Cloning - Lots of Different Methods

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36

Browser: Chrome 110

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Using the spread operator	31367270.0 Ops/sec
Using Object.assign	3469379.5 Ops/sec
Well-known Keys, Manually copying properties	719914304.0 Ops/sec
Well-known Keys, Create new object while copying	745517504.0 Ops/sec
Statically create new same object from scratch	739994112.0 Ops/sec
Iterate Copy - Object.entries()	2192555.2 Ops/sec
Iterate Copy - for..in	4871325.5 Ops/sec
Iterate Copy - Object.keys().forEach	2200771.2 Ops/sec
Iterate Copy - Object.entries() + for..of	2236970.0 Ops/sec
Iterable	419329.1 Ops/sec
JSON Copy	608850.4 Ops/sec
structuredClone	282568.2 Ops/sec
Object Assign pre-created	3350354.5 Ops/sec
Well-Known Keys, forEach	3417575.5 Ops/sec
Well-Known Keys, for..of	3714738.5 Ops/sec
Well-Known Keys, for..in	1563593.4 Ops/sec
Well-Known Numbered Keynames w/Known Length	1246324.4 Ops/sec
Object.keys() + map	2107892.5 Ops/sec
Object.entries() + map	1213452.5 Ops/sec
Well-known Keys, Manually copying properties, [] accessor	728586368.0 Ops/sec
Well-known Keys, Create new object while copying, [] accessor	736682240.0 Ops/sec
Well-known Keys, extract and create new object while copying, . accessor	724703360.0 Ops/sec
Well-known Keys, extract and create new object while copying, [] accessor	721244544.0 Ops/sec

Tests:

Using the spread operator
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {...firstObject};
Well-known Keys, Create new object while copying, [] accessor
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = { prop0: firstObject['prop0'], prop1: firstObject['prop1'], prop2: firstObject['prop2'], prop3: firstObject['prop3'], prop4: firstObject['prop4'], prop5: firstObject['prop5'] };
Well-known Keys, Manually copying properties, [] accessor
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; finalObject['prop0'] = firstObject['prop0']; finalObject['prop1'] = firstObject['prop1']; finalObject['prop2'] = firstObject['prop2']; finalObject['prop3'] = firstObject['prop3']; finalObject['prop4'] = firstObject['prop4']; finalObject['prop5'] = firstObject['prop5'];
Object.entries() + map
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; Object.entries(firstObject).map((k) => {finalObject[k[0]]=k[1];});
Object.keys() + map
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; Object.keys(firstObject).map((k) => {finalObject[k]=firstObject[k];});
Well-Known Numbered Keynames w/Known Length
const length = 5; const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; for (i=0;i<length;i++) { finalObject['prop'+i] = firstObject['prop'+i]; }
Well-Known Keys, for..in
const keys = ['prop0','prop1','prop2','prop3','prop4','prop5']; const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; for (let i in keys) { finalObject[keys[i]] = firstObject[keys[i]]; }
Well-Known Keys, for..of
const keys = ['prop0','prop1','prop2','prop3','prop4','prop5']; const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; for (let key of keys) { finalObject[key] = firstObject[key]; }
Well-Known Keys, forEach
const keys = ['prop0','prop1','prop2','prop3','prop4','prop5']; const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; keys.forEach((key)=>{finalObject[key]=firstObject[key]});
Object Assign pre-created
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {}; Object.assign(finalObject, firstObject);
Well-known Keys, extract and create new object while copying, . accessor
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let prop0 = firstObject.prop0; let prop1 = firstObject.prop1; let prop2 = firstObject.prop2; let prop3 = firstObject.prop3; let prop4 = firstObject.prop4; let prop5 = firstObject.prop5; const finalObject = { prop0, prop1, prop2, prop3, prop4, prop5 };
structuredClone
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = structuredClone(firstObject);
Iterable
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2, [Symbol.iterator]: function*() { let keys = Object.keys(this); for (let i=0;i<keys.length;i++) yield [ keys[i], this[keys[i]] ]; } }; let finalObject = {}; for (let [key,value] of firstObject) { finalObject[key] = value; }
Iterate Copy - Object.entries() + for..of
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; for (let [k,v] of Object.entries(firstObject)) { finalObject[k]=v; }
Iterate Copy - Object.keys().forEach
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; Object.keys(firstObject).forEach((key) => {finalObject[key] = firstObject[key];});
Iterate Copy - for..in
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; for (const property in firstObject) { finalObject[property] = firstObject[property]; }
Iterate Copy - Object.entries()
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; for (const [key, value] of Object.entries(firstObject)) { finalObject[key]=value; }
Statically create new same object from scratch
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 };
Well-known Keys, Create new object while copying
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = { prop0: firstObject.prop0, prop1: firstObject.prop1, prop2: firstObject.prop2, prop3: firstObject.prop3, prop4: firstObject.prop4, prop5: firstObject.prop5 };
Well-known Keys, Manually copying properties
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; finalObject.prop0 = firstObject.prop0; finalObject.prop1 = firstObject.prop1; finalObject.prop2 = firstObject.prop2; finalObject.prop3 = firstObject.prop3; finalObject.prop4 = firstObject.prop4; finalObject.prop5 = firstObject.prop5;
Using Object.assign
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = Object.assign({}, firstObject);
JSON Copy
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = JSON.parse(JSON.stringify(firstObject));
Well-known Keys, extract and create new object while copying, [] accessor
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let prop0 = firstObject['prop0']; let prop1 = firstObject['prop1']; let prop2 = firstObject['prop2']; let prop3 = firstObject['prop3']; let prop4 = firstObject['prop4']; let prop5 = firstObject['prop5']; const finalObject = { prop0, prop1, prop2, prop3, prop4, prop5 };

Run results for: JS Object Cloning - Lots of Different Methods

Using the spread operator

Well-known Keys, Create new object while copying, [] accessor

Well-known Keys, Manually copying properties, [] accessor

Object.entries() + map

Object.keys() + map

Well-Known Numbered Keynames w/Known Length

Well-Known Keys, for..in

Well-Known Keys, for..of

Well-Known Keys, forEach

Object Assign pre-created

Well-known Keys, extract and create new object while copying, . accessor

structuredClone

Iterable

Iterate Copy - Object.entries() + for..of

Iterate Copy - Object.keys().forEach

Iterate Copy - for..in

Iterate Copy - Object.entries()

Statically create new same object from scratch

Well-known Keys, Create new object while copying

Well-known Keys, Manually copying properties

Using Object.assign

JSON Copy

Well-known Keys, extract and create new object while copying, [] accessor