Run results for: Array constructor vs literal performance - 100000 items

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36 Edg/101.0.1210.53

Browser: Chrome 101

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Array constructor - 100000 items	820.9 Ops/sec
Array literal - 100000 items	754.4 Ops/sec
Array literal (assign by index) - 100000 items	795.6 Ops/sec
Array literal (explicit length) - 100000 items	826.6 Ops/sec

Script Preparation code:

var n = 10000;

function Person(name, age) {
  this.name = name;
  this.age = age;
}

Tests:

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

Run results for: Array constructor vs literal performance - 100000 items

Array constructor - 100000 items

Array literal - 100000 items

Array literal (assign by index) - 100000 items

Array literal (explicit length) - 100000 items