Run results for: reduce concat vs flat vs concat spread vs reduce spread

Run details:

User agent: Mozilla/5.0 (Linux; Android 12; Pixel 4a) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.115 Mobile Safari/537.36

Browser: Chrome Mobile 104

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
reduce + Array.prototype.concat	67561.2 Ops/sec
Array.prototype.flat	379.1 Ops/sec
concat(...)	86355.1 Ops/sec
reduce spread	10073.9 Ops/sec

Script Preparation code:

var params = [
    [1, 2],
    ["hello", true, 7],
    Array(10000).fill(4),
];

Tests:

reduce + Array.prototype.concat
const x = params.reduce((acc, val) => acc.concat(val), []);
Array.prototype.flat
const x = params.flat(1);
concat(...)
const x = [].concat(...params)
reduce spread
const x = params.reduce((acc, val) => [...acc, ...val], []);