Run results for: String test comparison - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.19 Safari/537.36

Browser: Chrome 77

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
index	6978466.0 Ops/sec
charAt()	6881000.0 Ops/sec
startsWith()	6925294.0 Ops/sec
slice()	6283776.0 Ops/sec
RegExp	5481562.0 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();