Run results for: replace vs substring vs slice from END

Test the performance of replace() vs substring() vs slice() when replacing a char at the beginning of a (in this case uri query-)string that may or may not be there. Added the combined brackets[ ] + substr() method, since it's always the first char we wan't to pop off. Inspired by https://jsperf.com/replace-or-substr. Note: could not get 'let' and 'const' to work. Well, too bad...

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.5.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.5.1

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
substring	6916582.5 Ops/sec
replace inline regex	6226844.0 Ops/sec
replace compiled regex var	5252527.5 Ops/sec
slice	8889427.0 Ops/sec

Script Preparation code:

var strIn = 'https://www.data-xata.com/all-servers.html';
var strOut = '';
var regex = /\.html$/;

Tests:

substring
strOut = strIn.substring(0,strIn.length-5) + '.JS'
replace inline regex
strOut = strIn.replace(/\.html$/, '.JS');
replace compiled regex var
strOut = strIn.replace(regex, '.JS');
slice
strOut = strIn.slice(0,-5) + '.JS'

Run results for: replace vs substring vs slice from END

substring

replace inline regex

replace compiled regex var

slice