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/131.0.0.0 Safari/537.36 Edg/131.0.0.0

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: 4 months ago

Test name	Executions per second
reduce + Array.prototype.concat	53186.3 Ops/sec
Array.prototype.flat	5918.4 Ops/sec
concat(...)	183125.2 Ops/sec
reduce spread	21033.2 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], []);