Run results for: Array concat vs spread vs push spread, loop, apply

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/113.0.5672.121 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 113

Operating system: iOS 16.3

Device Platform: Mobile

Date tested: 11 months ago

Test name	Executions per second
Array.prototype.concat	3204636.0 Ops/sec
spread operator	3036037.0 Ops/sec
Push Spread	2002671.0 Ops/sec
Push Apply	2319093.0 Ops/sec
Push Loop	3038327.0 Ops/sec

Script Preparation code:

var subarrs = [
 [ "hello", true, 7 ],
 [ "yes", "no", "maybe", false, 27 ],
 [ 16, "I", "wonder", "what", "will", "be", "fastest"]
];

Tests:

Array.prototype.concat
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other = other.concat(subarrs[i]); } return other;
spread operator
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other = [ ...other, ...subarrs[i] ] } return other;
Push Spread
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other.push(...subarrs[i]); } return other;
Push Apply
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other.push.apply(other, subarrs[i]); } return other;
Push Loop
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ for (var jarr = subarrs[i], jen = jarr.length, j = 0; j < jen; j++){ other.push(jarr[j]); } } return other;

Run results for: Array concat vs spread vs push spread, loop, apply

Compare the new ES6 spread operator with the traditional concat() method and push

Array.prototype.concat

spread operator

Push Spread

Push Apply

Push Loop