Run results for: for with saved length vs evaluation on every loop cycle

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36

Browser: Chrome 78

Operating system: Linux

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
With saved length	79186.6 Ops/sec
Evaluating length on every loop cycle	53372.9 Ops/sec

Script Preparation code:

var arr = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99]

Tests:

With saved length
for (let i = 0, length = arr.length; i < length; i++) arr[i] * arr[i]
Evaluating length on every loop cycle
for (let i = 0; i < arr.length; i++) arr[i] * arr[i]

Run results for: for with saved length vs evaluation on every loop cycle

With saved length

Evaluating length on every loop cycle