Run results for: Object.assign vs. JSON String/Parse

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 12_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 [FBAN/FBIOS;FBDV/iPhone11,8;FBMD/iPhone;FBSN/iOS;FBSV/12.4.1;FBSS/2;FBID/phone;FBLC/th_TH;FBOP/5;FBCR/TRUE-H]

Browser: Mobile Safari 12

Operating system: iOS 12.4.1

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
Spread operator	16076920.0 Ops/sec
JSON Parse	15542350.0 Ops/sec
Object.assign	15157410.0 Ops/sec

Tests:

Spread operator
var n = {foo: 'bar', hello: [{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'}]}; while(n.length < 1000) { n = [...n]; }
JSON Parse
var n = {foo: 'bar', hello: [{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'}]}; while(n.length < 1000) { n = JSON.parse(JSON.stringify(n)) }
Object.assign
var n = {foo: 'bar', hello: [{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'},{hello: 'world', foo: 'bar'}]}; while(n.length < 1000) { n = Object.assign({}, n); }

Run results for: Object.assign vs. JSON String/Parse

Creating a "new" object reference every time

Spread operator

JSON Parse

Object.assign