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/605.1.15 (KHTML, like Gecko) Version/17.6 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 months ago

Test name	Executions per second
.startsWith forEach	3857820.8 Ops/sec
.charAt forEach	8148024.0 Ops/sec
[0] forEach	7509406.5 Ops/sec
.match forEach	3467860.0 Ops/sec
.startsWith	3963526.0 Ops/sec
.charAt	9492885.0 Ops/sec
[0]	8493414.0 Ops/sec
.match	7197429.5 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(/^\*/)}

;