Run results for: Array.concat vs Array.prototype.concat.apply

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0

Browser: Firefox 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array.concat	46848.1 Ops/sec
Array.prototype.concat.apply	48155.1 Ops/sec
Array.prototype.concat.apply short form	47322.9 Ops/sec
Array.prototype.concat.apply short form without new empty array instance in apply	48142.0 Ops/sec
Array.prototype.concat.apply short form without new empty array at all	48857.9 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));

Tests:

Array.concat
var others = array1.concat(array2, array3, array4, array5);
Array.prototype.concat.apply
var others = Array.prototype.concat.apply([], [array1, array2, array3, array4, array5]);
Array.prototype.concat.apply short form
var others = [].concat.apply([], [array1, array2, array3, array4, array5]);
Array.prototype.concat.apply short form without new empty array instance in apply
var others = [].concat.apply(array1, [array2, array3, array4, array5]);
Array.prototype.concat.apply short form without new empty array at all
var others = array1.concat.apply(array1, [array2, array3, array4, array5]);

Run results for: Array.concat vs Array.prototype.concat.apply

Compare direct concat call with apply for multiple arrays concatenation

Array.concat

Array.prototype.concat.apply

Array.prototype.concat.apply short form

Array.prototype.concat.apply short form without new empty array instance in apply

Array.prototype.concat.apply short form without new empty array at all