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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) QtWebEngine/6.6.1 Chrome/112.0.5615.213 Safari/537.36

Browser: Chrome 112

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one month ago

Test name	Executions per second
Array.prototype.concat	1903515.0 Ops/sec
spread operator	2603881.0 Ops/sec
Push Spread	3693135.0 Ops/sec
Push Apply	3674975.0 Ops/sec
Push Loop	4124472.0 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