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

Test name

Executions per second

✓ Push Loop

7,975,916 Ops/sec

Assign length loop

7,143,618 Ops/sec

minified assign loop

6,562,028 Ops/sec

Push Apply

6,462,512 Ops/sec

Push Spread

6,327,984 Ops/sec

Array.prototype.concat

6,169,730 Ops/sec

spread operator

2,202,034 Ops/sec

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];