Run results for: undefined checks on property in if condition

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.1 Safari/605.1.15

Browser: Safari 13

Operating system: Mac OS X 10.14.6

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
implicit boolean conversion	8631457.0 Ops/sec
explicit boolean conversion	8323123.0 Ops/sec
triple inequality against undefined	2874510.0 Ops/sec
typeof	8740676.0 Ops/sec

Script Preparation code:

var obj = {a: 1, b: "b", c: undefined};

Tests:

implicit boolean conversion
if (obj.c) { console.log(obj.c); }
explicit boolean conversion
if (!!obj.c) { console.log(obj.c); }
triple inequality against undefined
if (obj.c !== undefined) { console.log(obj.c); }
typeof
if (typeof obj.c !== "undefined") { console.log(obj.c); }