Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Safari/605.1.15
Safari 15
Mac OS X 10.15.6
Desktop
3 years ago
Test name Executions per second
Array constructor - 10 items 11231896.0 Ops/sec
Array literal - 10 items 30943204.0 Ops/sec
Array literal (assign by index) - 10 items 25819930.0 Ops/sec
Array literal (explicit length) - 10 items 3453798.8 Ops/sec
Tests:
  • Array constructor - 10 items

    x
     
    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;
    }