Run results for: Array Indexation vs. Array Access

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser: Chrome 117

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
array.includes at the beggining	3646802.0 Ops/sec
array.includes at the end	3585005.2 Ops/sec
Indexation THEN check at the beggining	913455.5 Ops/sec
Indexation THEN check at the end	916763.0 Ops/sec

Script Preparation code:

var testArray = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'nineteen', 'twenty'];

Tests:

array.includes at the beggining
testArray.includes('two'); testArray.includes('three'); testArray.includes('four'); testArray.includes('five');
array.includes at the end
testArray.includes('twenty'); testArray.includes('nineteen'); testArray.includes('eighteen'); testArray.includes('seventeen');
Indexation THEN check at the beggining
const testObject = {}; for (const key in testArray) testObject[key] = true; testObject['one']; testObject['two']; testObject['three']; testObject['four'];
Indexation THEN check at the end
const testObject = {}; for (const key in testArray) testObject[key] = true; testObject['twenty']; testObject['nineteen']; testObject['eighteen']; testObject['seventeen'];

Run results for: Array Indexation vs. Array Access

Checks whether it is faster to index an array before using it, or just using it as is, when few reads are involved

array.includes at the beggining

array.includes at the end

Indexation THEN check at the beggining

Indexation THEN check at the end