Run results for: forEach vs For of and startsWith 2 - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser: Chrome 126

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 months ago

Test name	Executions per second
.startsWith forEach	20394226.0 Ops/sec
.charAt forEach	13527764.0 Ops/sec
[0] forEach	20459586.0 Ops/sec
.match forEach	5393934.5 Ops/sec
.startsWith	20417272.0 Ops/sec
.charAt	13789327.0 Ops/sec
[0]	20619168.0 Ops/sec
.match	5564020.0 Ops/sec

Script Preparation code:

var strs = [
    '',
    '*',
    '#',
    '*short',
    '#short',
    '*'.padEnd(2500, '-'),
    '#'.padEnd(2500, '-'),
];

Tests:

.startsWith forEach
strs.forEach(str => {str.startsWith('*')})
.charAt forEach
strs.forEach(str => {str.charAt(0) === '*'})
[0] forEach
strs.forEach(str => {str[0] === '*'})
.match forEach
strs.forEach(str => {str.match(/^\*/)})
.startsWith
for(const str of strs) {str.startsWith('*')}
.charAt
for(const str of strs) {str.charAt(0) === '*'}
[0]
for(const str of strs) {str[0] === '*'}
.match
for(const str of strs) {str.match(/^\*/)}

;