Run results for: Array constructor vs literal performance

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Safari/537.36

Browser: Chrome 85

Operating system: Mac OS X 10.15.6

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array constructor - 10 items	5364988.0 Ops/sec
Array literal - 10 items	28669620.0 Ops/sec
Array literal (assign by index) - 10 items	28688990.0 Ops/sec
Array literal (explicit length) - 10 items	7094730.0 Ops/sec
Array constructor - 1000 items	869656.9 Ops/sec
Array literal - 1000 items	254121.5 Ops/sec
Array literal (assign by index) - 1000 items	280799.5 Ops/sec
Array literal (explicit length) - 1000 items	848051.4 Ops/sec
Array constructor - 100000 items	5090.6 Ops/sec
Array literal - 100000 items	1591.1 Ops/sec
Array literal (assign by index) - 100000 items	1679.7 Ops/sec
Array literal (explicit length) - 100000 items	5251.0 Ops/sec

Tests:

Array constructor - 10 items
var n = 10; var arr = new Array(n); for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal - 10 items
var n = 10; var arr = []; for (var i = 0; i < n; i++) { arr.push(i); }
Array literal (assign by index) - 10 items
var n = 10; var arr = []; for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal (explicit length) - 10 items
var n = 10; var arr = []; arr.length = n; for (var i = 0; i < n; i++) { arr[i] = i; }
Array constructor - 1000 items
var n = 1000; var arr = new Array(n); for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal - 1000 items
var n = 1000; var arr = []; for (var i = 0; i < n; i++) { arr.push(i); }
Array literal (assign by index) - 1000 items
var n = 1000; var arr = []; for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal (explicit length) - 1000 items
var n = 1000; var arr = []; arr.length = n; for (var i = 0; i < n; i++) { arr[i] = i; }
Array constructor - 100000 items
var n = 100000; var arr = new Array(n); for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal - 100000 items
var n = 100000; var arr = []; for (var i = 0; i < n; i++) { arr.push(i); }
Array literal (assign by index) - 100000 items
var n = 100000; var arr = []; for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal (explicit length) - 100000 items
var n = 100000; var arr = []; arr.length = n; for (var i = 0; i < n; i++) { arr[i] = i; }