Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.1 Safari/605.1.15
Safari 15
Mac OS X 10.15.7
Desktop
3 years ago
Test name Executions per second
Cache length 9692.9 Ops/sec
Do not cache 4735.3 Ops/sec
Script Preparation code:
AخA
 
var arr = [];
var count = 1000;
for(var i = 0; i<count; i++)
{
  arr.push(i);
}
Tests:
  • Cache length

     
    var arrLen = arr.length;
    var sum = 0;
    for (var i = 0; i < arrLen; i++){
      sum = arr[i];
    }
  • Do not cache

     
    var sum = 0;
    for (var i = 0; i < arr.length; i++){
      sum = arr[i];
    }