Run results for: dom array initialization: preallocate vs push

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 4 months ago

Test name	Executions per second
Preallocate	842075.2 Ops/sec
Push	843771.4 Ops/sec

Script Preparation code:

let A=(a)=>{return document.createElement(a)}
let B=[A('a'),A('div'),A('span'),A('p'),A('input')];
let D=(I,J)=>{const E=B[I].cloneNode();E.className=J;return E;}

Tests:

Preallocate
let C=[B[0].cloneNode(),B[0].cloneNode(),B[2].cloneNode(),B[2].cloneNode(),B[1].cloneNode(),B[4].cloneNode()] C[0].className='a b c' C[1].className='a b c' C[2].className='d e f' C[3].className='d e f' C[4].className='a b c' C[5].className='a b c'
Push
let C = new Array(6); C[0]=B[0].cloneNode() C[0].className='a b c' C[1]=C[0].cloneNode() C[2]=B[2].cloneNode() C[2].className='d e f' C[3]=C[2].cloneNode() C[4]=B[1].cloneNode() C[4].className='a b c' C[5]=B[4].cloneNode() C[5].className='a b c'
FuncCombined
let C=[D(0,'a b c'),D(0,'a b c'),D(2,'d e f'),D(2,'d e f'),D(1,'a b c'),D(4,'a b c')]

Run results for: dom array initialization: preallocate vs push

Preallocate

Push

FuncCombined