Run results for: substr vs startsWith

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Browser: Chrome 67

Operating system: Mac OS X 10.13.3

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
substr	10507110.0 Ops/sec
startsWith	6673371.0 Ops/sec

Script Preparation code:

var str = "abcdefghijklmnopqrstuvwxyz";

Tests: