Run results for: Caching length property vs getting it each time in the loop

Run details:

User agent: Mozilla/5.0 (Windows Phone 10.0; Android 6.0.1; Microsoft; Lumia 950 XL Dual SIM) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Mobile Safari/537.36 Edge/14.14915

Browser: Chrome Mobile 51

Operating system: Windows Phone 10.0

Device Platform: Lumia 950

Date tested: 7 years ago

Test name	Executions per second
Cache length	5576.0 Ops/sec
Do not cache	3919.2 Ops/sec

Script Preparation code:

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]; }

Run results for: Caching length property vs getting it each time in the loop

save length of the array in the variable vs get it the loop

Cache length

Do not cache