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

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Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/111.0
Firefox 111
Mac OS X 10.15
Desktop
2 years ago
Test name Executions per second
Array constructor - 100000 items 2562.1 Ops/sec
Array literal - 100000 items 2818.7 Ops/sec
Array literal (assign by index) - 100000 items 2852.0 Ops/sec
Array literal (explicit length) - 100000 items 2906.2 Ops/sec
Script Preparation code:
​x
 
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);
    }