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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser: Chrome 69

Operating system: Windows

Device Platform: Desktop

Date tested: 6 years ago

Script Preparation code:

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

AخA
 
var hasOwnProperty = Object.prototype.hasOwnProperty;var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };

Tests:

undefined
undefined !== obj.d;
undefined !== obj.d;
typeof
'undefined' !== typeof obj.d;
'undefined' !== typeof obj.d;
in
'd' in obj;
'd' in obj;
hasOwnProperty
hasOwnProperty.call( obj, 'd' );
hasOwnProperty.call( obj, 'd' );
bool
!! obj.d;
!! obj.d;