Run results for: Array.includes vs. Dictionary lookup

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36

Browser: Chrome 80

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Array.includes	4697428.5 Ops/sec
Dictionary lookup	5488642.5 Ops/sec

Script Preparation code:

var a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
var b = {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9};
var randomIndex = Math.floor(Math.random() * 10);

Tests:

Array.includes
a.includes(randomIndex);
Dictionary lookup
b[randomIndex];