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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:84.0) Gecko/20100101 Firefox/84.0

Browser: Firefox 84

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 4 years ago

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]); }
spread operator
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other = [ ...other, ...subarrs[i] ] }
Push Spread
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other.push(...subarrs[i]); }
Push Apply
var other = [ 1, 2, 3 ] for (var len = subarrs.length, i = 0; i < len; i++){ other.push.apply(other, subarrs[i]); }
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]); } }
Assign length loop
var other = [1, 2, 3]; for (var i = 0, j, m, a, n = subarrs.length; i < n; ++i) for (j = 0, a = subarrs[i], m = a.length; j < m; ++j) other[other.length] = a[j];
minified assign loop
for(var r,s,a,e=[1,2,3],g=0,h=subarrs.length;g<h;++g)for(r=0,s=(a=subarrs[g]).length;r<s;++r)e[e.length]=a[r];