Run results for: A.push(B) V.S. [ ...A, B ]

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:99.0) Gecko/20100101 Firefox/99.0

Browser: Firefox 99

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Control (for push)	254208.6 Ops/sec
Spread	2231.5 Ops/sec

Script Preparation code:

window.top.tests = {control:[], spread:[]};
window.test = (new Array(10)).fill(null);
window.cutoff = 5000;

Tests:

Control (for push)
for (let element of window.test) window.top.tests.control.push(element); if (window.top.tests.control.length > window.cutoff) { window.top.tests.control = []; console.log('reset control'); }
Spread
for (let element of window.test) window.top.tests.spread = [ ...window.top.tests.spread, element ]; if (window.top.tests.spread.length > window.cutoff) { window.top.tests.spread = []; console.log('reset spread'); }