Caching length property vs getting it each time in the loop
save length of the array in the variable vs get it the loop
Date tested:
one year ago
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/113.0
Test name
Executions per second
Cache length
937027.1 Ops/sec
Do not cache
939180.4 Ops/sec
Benchmark definition (click to collapse):
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]; }
Open this result on MeasureThat.net