Run results for: String test comparison - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36

Browser: Chrome 76

Operating system: Mac OS X 10.11.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
index	3941150.0 Ops/sec
charAt()	3878600.0 Ops/sec
startsWith()	3931650.0 Ops/sec
slice()	3594638.0 Ops/sec
RegExp	3180350.0 Ops/sec

Website performance monitoring

Script Preparation code:

var str = '!foo bar baz';
var noop = Function.prototype;

Tests:

index
if (str[0] === '!') noop();
charAt()
if (str.charAt(0) === '!') noop();
startsWith()
if (str.startsWith('!')) noop();
slice()
if (str.slice(0, 1) === '!') noop();
RegExp
var pattern = /^!/; if (pattern.test(str)) noop();