Run results for: padLeft comparison

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36 Edg/117.0.2045.60

Browser: Chrome 117

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
padLeft	209498.4 Ops/sec
slice	202395.1 Ops/sec
slice template literal	198990.0 Ops/sec
pad	142353.4 Ops/sec

HTML Preparation code:

<script>
const buffer = crypto.getRandomValues(new Uint8Array(16))

const z = '0'
const zz = '00'

function pad(pad, str) {
  if (typeof str === 'undefined') 
    return pad

  return (pad + str).slice(-pad.length)
}
</script>

Tests:

padLeft
for (let string = '', i = 0; i < buffer.length; i++) { string += buffer[i].toString(16).padStart(2, z) }
slice
for (let string = '', i = 0; i < buffer.length; i++) { string += (zz + buffer[i].toString(16)).slice(-2) }
slice template literal
for (let string = '', i = 0; i < buffer.length; i++) { string += `${zz}${buffer[i].toString(16)}`.slice(-2) }
pad
for (let string = '', i = 0; i < buffer.length; i++) { string += pad(zz, buffer[i].toString(16)) }

Run results for: padLeft comparison

padLeft

slice

slice template literal

pad