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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36 Edg/103.0.1264.62

Browser: Chrome 103

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
reduce + Array.prototype.concat	200148.9 Ops/sec
Array.prototype.flat	688.1 Ops/sec
concat(...)	201916.4 Ops/sec
reduce spread	18674.7 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], []);