Run results for: object creation: object mutation vs hidden class vs combined vs field declaration

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
With mutation	192.8 Ops/sec
constructor	353.6 Ops/sec
with constructor and mutation	196.0 Ops/sec

Tests:

With mutation
class SomeClass { one = "" two = 1 } for (var i = 0; i < 10_000; i++) { const obj = new SomeClass() obj.two = 2 }
constructor
class SomeClass { one = "" constructor(two) { this.two = two } } for (var i = 0; i < 10_000; i++) { const obj = new SomeClass(2) }
with constructor and mutation
class SomeClass { one = "" two = 1 constructor(two) { this.two = two } } for (var i = 0; i < 10_000; i++) { const obj = new SomeClass(2) }
declaration and constructor
class SomeClass { one constructor(one) { this.one = one } } for (var i = 0; i < 10_000; i++) { const obj = new SomeClass(2) }