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

Run details:

User agent: Mozilla/5.0 (Linux; Android 11; M2004J19C Build/RP1A.200720.011) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.6099.193 Mobile Safari/537.36

Browser: Chrome Mobile 120

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Cache length

5K/s

Do not cache

2K/s

View exact numbers

Test name	Executions per second
✓ Cache length	4,653 Ops/sec
Do not cache	2,387 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