Run results for: undefined vs. typeof vs. in vs. hasOwnProperty big object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36

Browser: Chrome 68

Operating system: Windows

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
undefined	4052044.0 Ops/sec
typeof	12709811.0 Ops/sec
in	10360009.0 Ops/sec
hasOwnProperty	10441775.0 Ops/sec
bool	12906578.0 Ops/sec
keys	2922956.0 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5,  e1: 5, e2: 5, e3: 5, e4: 5, e5: 5, e6: 5, e7: 5, e8: 5, e9: 5, e0: 5, ea: 5, eb: 5, ec: 5, ed: 5, ee: 5, ef: 5, eg: 5, eh: 5, ei: 5, ej: 5, ek: 5, el: 5, em: 5, en: 5, eo: 5, ep: 5, eq: 5, er: 5, es: 5, et: 5, eu: 5, ev: 5, ew: 5, ex: 5, ey: 5, ez: 5, f1: 5, f2: 5, f3: 5, f4: 5, f5: 5, f6: 5, f7: 5, f8: 5, f9: 5, f0: 5, fa: 5, fb: 5, fc: 5, fd: 5, fe: 5, ff: 5, fg: 5, fh: 5, fi: 5, fj: 5, fk: 5, fl: 5, fm: 5, fn: 5, fo: 5, fp: 5, fq: 5, fr: 5, fs: 5, ft: 5, fu: 5, fv: 5, fw: 5, fx: 5, fy: 5, fz: 5, g1: 5, g2: 5, g3: 5, g4: 5, g5: 5, g6: 5, g7: 5, g8: 5, g9: 5, g0: 5, ga: 5, gb: 5, gc: 5, gd: 5, ge: 5, gf: 5, gg: 5, gh: 5, gi: 5, gj: 5, gk: 5, gl: 5, gm: 5, gn: 5, go: 5, gp: 5, gq: 5, gr: 5, gs: 5, gt: 5, gu: 5, gv: 5, gw: 5, gx: 5, gy: 5, gz: 5};

Tests:

undefined
undefined !== obj.gr;
typeof
'undefined' !== typeof obj.gr;
in
'gr' in obj;
hasOwnProperty
obj.hasOwnProperty( 'gr' );
bool
!! obj.gr;
keys
Object.keys(obj).includes('gr');

Run results for: undefined vs. typeof vs. in vs. hasOwnProperty big object

Object lookup performance

undefined

typeof

in

hasOwnProperty

bool

keys