Run results for: undefined vs. typeof vs. in vs. hasOwnProperty vs Object.prototype.hasOwnProperty

Run details:

User agent: Mozilla/5.0 (Linux; Android 9; SAMSUNG SM-N950F) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/12.1 Chrome/79.0.3945.136 Mobile Safari/537.36

Browser: Chrome Mobile 79

Operating system: Android

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
undefined	1462487.4 Ops/sec
typeof	4575021.5 Ops/sec
in	4464992.0 Ops/sec
hasOwnProperty	4178256.0 Ops/sec
bool	4431711.0 Ops/sec
Object.prototype.hasOwnProperty	791699.4 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };
function hasOwn (obj, key) {
  return hasOwnProperty.call(obj, key)
}

Tests:

undefined
undefined !== obj.d;
typeof
'undefined' !== typeof obj.d;
in
'd' in obj;
hasOwnProperty
obj.hasOwnProperty( 'd' );
bool
!! obj.d;
Object.prototype.hasOwnProperty
hasOwn(obj, 'd')

Run results for: undefined vs. typeof vs. in vs. hasOwnProperty vs Object.prototype.hasOwnProperty

Object lookup performance

undefined

typeof

in

hasOwnProperty

bool

Object.prototype.hasOwnProperty