Run results for: concat.apply short form new array vs flat

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.9999.0 Safari/537.36

Browser: Chrome 102

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
concat.apply	1130603.0 Ops/sec
flat	8192.7 Ops/sec

Script Preparation code:

var array1 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array2 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array3 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array4 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array5 = Array(400).fill().map(() => Math.round(Math.random() * 40));

var allArrays = [array1, array2, array3, array4, array5];

Tests:

concat.apply
var others = [].concat.apply([], allArrays);
flat
var others = allArrays.flat()

Run results for: concat.apply short form new array vs flat

Comparing Array.prototype.concat.apply short form with empty array vs flat

concat.apply

flat