Benchmark: Array constructor vs literal performance

Array constructor vs literal performance (version: 0)

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; }

Rendered benchmark preparation results:

Previous results

Test case name	Result
Array constructor - 10 items
Array literal - 10 items
Array literal (assign by index) - 10 items
Array literal (explicit length) - 10 items
Array constructor - 1000 items
Array literal - 1000 items
Array literal (assign by index) - 1000 items
Array literal (explicit length) - 1000 items
Array constructor - 100000 items
Array literal - 100000 items
Array literal (assign by index) - 100000 items
Array literal (explicit length) - 100000 items

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Latest run results:

Run details: (Test run date: 4 years ago)

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/OS: Chrome 85 on Mac OS X 10.15.6

Test name	Executions per second
Array constructor - 10 items	5364987.5 Ops/sec
Array literal - 10 items	28669618.0 Ops/sec
Array literal (assign by index) - 10 items	28688986.0 Ops/sec
Array literal (explicit length) - 10 items	7094729.5 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

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