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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/111.0

Browser: Firefox 111

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Array.prototype.concat	5577.1 Ops/sec
spread operator	3334.4 Ops/sec
Push Spread	18581.5 Ops/sec
Push Apply	19248.6 Ops/sec
Push Loop	12875.4 Ops/sec

Script Preparation code:

var subarrsBase = [
 [ "hello", true, 7 ],
 [ "yes", "no", "maybe", false, 27 ],
 [ 16, "I", "wonder", "what", "will", "be", "fastest"]
];

var subarrs = subarrsBase.map(arr => {
  let newArr = [...arr];
  for(let i = 0; i < 10; i++) {
    newArr = [...newArr, ...newArr];
  }
  return newArr;
})

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 long 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