Run details:
Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36
Chrome 57
Fedora
Other
8 years ago
Test name Executions per second
for 3 7597.5 Ops/sec
for 4 3797.0 Ops/sec
copy 102593.8 Ops/sec
Script Preparation code:
x
 
var arr = [];
  for (var i = 0; i < 1000; i++) {
    arr[i] = i;
  }
  function someFn(ix) {
    return ix * 5;
  }
Tests:
  • for 3

     
    var l = arr.length;
    var result=0;
    for (var i = 0; i < l; i++) {
      result += arr[i] * 5;
    }
  • for 4

     
    var result=0;
    for (var i = 0; i < arr.length; i++) {
      result += arr[i] * 5;
    }
  • copy

     
    var arr = [];
      for (var i = 0; i < 1000; i++) {
        arr[i] = i;
      }
    var result=0;
    for (var i = 0; i < arr.length; i++) {
      result += arr[i] * 5;
    }