Run results for: undefined vs. typeof vs. in vs. hasOwnProperty my3

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 YaBrowser/20.3.1.195 Yowser/2.5 Yptp/1.23 Safari/537.36

Browser: Yandex Browser 20

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
ue	4221987.0 Ops/sec
aue	12650610.0 Ops/sec
eu	4261572.0 Ops/sec
eau	12895280.0 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };

Tests:

ue
undefined !== obj.d;
aue
'undefined' !== typeof obj.d;
eu
obj.d === undefined;
eau
typeof obj.d === 'undefined';

Run results for: undefined vs. typeof vs. in vs. hasOwnProperty my3

Object lookup performance

ue

aue

eu

eau