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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0

Browser: Firefox 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array constructor - 100000 items	557.7 Ops/sec
Array literal - 100000 items	451.4 Ops/sec
Array literal (assign by index) - 100000 items	542.0 Ops/sec
Array literal (explicit length) - 100000 items	555.0 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); }