Run results for: indexOf() === 0 vs lastindexof( ,0) === 0 vs startsWith() vs idx

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.60 Safari/537.36 Edg/100.0.1185.29

Browser: Chrome 100

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
lastIndexOf	46533200.0 Ops/sec
indexOf	849161700.0 Ops/sec
startsWith	61352640.0 Ops/sec
idx	901954000.0 Ops/sec
idx #2	897648300.0 Ops/sec
substr	889221000.0 Ops/sec

Tests:

lastIndexOf
var str = "Hello world, welcome to the universe."; var n = str.lastIndexOf("Hello", 0) === 0;
indexOf
var str = "Hello world, welcome to the universe."; var n = str.indexOf("Hello") === 0;
startsWith
var str = "Hello world, welcome to the universe."; var n = str.startsWith("Hello");
idx
var str = "Hello world, welcome to the universe."; var n = str[0] === 'H' && str[1] === 'e' && str[2] === 'l' && str[3] === 'l' && str[4] === 'o';
idx #2
var str = "Hello world, welcome to the universe."; var n = str[0] == 'H' && str[1] == 'e' && str[2] == 'l' && str[3] == 'l' && str[4] == 'o';
substr
var str = "Hello world, welcome to the universe."; var n = str.substring(0, 5) === 'Hello';

Run results for: indexOf() === 0 vs lastindexof( ,0) === 0 vs startsWith() vs idx

lastIndexOf

indexOf

startsWith

idx

idx #2

substr