Run results for: typeof val === "undefined" vs !val vs val === undefined

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser: Chrome 112

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
typeof	1129645.0 Ops/sec
negate	1189621.9 Ops/sec
equality	708106.0 Ops/sec

Script Preparation code:

const undef = undefined
function checkType(val) {
  return typeof val === 'undefined'
}
function negate(val) {
  return !val
}
function equality(val) {
  return val === undefined;
}

Tests:

typeof
const undef = undefined checkType(undef)
negate
const undef = undefined negate(undef)
equality
const undef = undefined equality(undef)