Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12) AppleWebKit/602.1.50 (KHTML, like Gecko) Version/10.0 Safari/602.1.50
Safari 10
Mac OS X 10.12
Other
8 years ago
Test name Executions per second
Array constructor - 10 items 6457469.0 Ops/sec
Array literal - 10 items 14475793.0 Ops/sec
Array literal (assign by index) - 10 items 12999893.0 Ops/sec
Array literal (explicit length) - 10 items 11770350.0 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;
    }