Run results for: in !== hasOwnProperty

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36

Browser: Chrome 79

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
"cMemberId" in vUserInfo	801729856.0 Ops/sec
vUserInfo.cMemberId !== undefined	6710255.5 Ops/sec
vUserInfo.cMemberId === undefined	6695760.5 Ops/sec
vUserInfo.hasOwnProperty("cMemberId")	93191984.0 Ops/sec

Script Preparation code:

const vUserInfo = {cMemberId: 1}

Tests:

"cMemberId" in vUserInfo
const vUserInfo = {cMemberId: 1} "cMemberId" in vUserInfo
vUserInfo.cMemberId !== undefined
const vUserInfo = {cMemberId: 1} vUserInfo.cMemberId !== undefined
vUserInfo.cMemberId === undefined
const vUserInfo = {cMemberId: 1} vUserInfo.cMemberId === undefined
vUserInfo.hasOwnProperty("cMemberId")
const vUserInfo = {cMemberId: 1} vUserInfo.hasOwnProperty("cMemberId")