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

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.6

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
Array.prototype.concat	3618.3 Ops/sec
spread operator	6559.6 Ops/sec
Push Spread	4477.4 Ops/sec
Push Apply	7933.8 Ops/sec
Push Loop	9415.1 Ops/sec

Script Preparation code:

var subarrs = [
 new Array(10000).fill(0).map(() => Math.random()),
 new Array(10000).fill(0).map(() => Math.random() || 0),
 new Array(10000).fill(0).map(() => String(Math.random())),
];

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 Huge arrays

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

Array.prototype.concat

spread operator

Push Spread

Push Apply

Push Loop