Run results for: undefined vs. typeof vs. in vs. hasOwnProperty 7

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36 Edg/84.0.522.63

Browser: Chrome 84

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
a	4300212.0 Ops/sec
b	3260632.0 Ops/sec
c	5529493.0 Ops/sec
d	6438431.0 Ops/sec
e	6425598.0 Ops/sec
f	5977760.0 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };
var undef = undefined;
function a() {'use strict';undef !== obj.d}
function b() {'use strict';undefined !== obj.d}
function c() {'use strict';'d' in obj}
function d() {'use strict';!!obj.d}
function e() {'use strict';'undefined' !== typeof obj.d;}
function f() {'use strict';obj.hasOwnProperty( 'd' );}

Tests:

a
a()
b
b()
c
c()
d
d()
e
e()
f
f()

Run results for: undefined vs. typeof vs. in vs. hasOwnProperty 7

Object lookup performance

a

b

c

d

e

f