Run results for: Compare detecting object keys starting with "on"

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:99.0) Gecko/20100101 Firefox/99.0

Browser: Firefox 99

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
RegEx	686168.0 Ops/sec
Substr	625773.0 Ops/sec
charAt	571589.8 Ops/sec
Array access	532780.2 Ops/sec

Script Preparation code:

function noop(){};

const attrs = {
  id: 'test',
  onclick: noop,
  class: 'test'
};

function getAttrs() {
  return attrs;
}

function getElem() {
  return document.createElement('div');
}

Tests:

RegEx
const el = getElem(); const attrs = getAttrs(); const re = /^on/; Object.keys(attrs).forEach( attr => { if( re.test( attr ) ) { el[ attr ] = attrs[ attr ]; } else { el.setAttribute( attr, attrs[ attr ] ); } });
Substr
const el = getElem(); const attrs = getAttrs(); Object.keys(attrs).forEach( attr => { if( attr.substr( 0, 2 ) === 'on' ) { el[ attr ] = attrs[ attr ]; } else { el.setAttribute( attr, attrs[ attr ] ); } });
charAt
const el = getElem(); const attrs = getAttrs(); Object.keys(attrs).forEach( attr => { if( attr.charAt( 0 ) === 'o' && attr.charAt( 1 ) === 'n' ) { el[ attr ] = attrs[ attr ]; } else { el.setAttribute( attr, attrs[ attr ] ); } });
Array access
const el = getElem(); const attrs = getAttrs(); Object.keys(attrs).forEach( attr => { if( attr[ 0 ] === 'o' && attr[ 1 ] === 'n' ) { el[ attr ] = attrs[ attr ]; } else { el.setAttribute( attr, attrs[ attr ] ); } });

Run results for: Compare detecting object keys starting with "on"

RegEx

Substr

charAt

Array access