JS: Access Property

By Xah Lee. Date: 2013-11-19. Last updated: 2026-01-25.

Get

syntax	use proto chain	work with Symbol Key
`obj.k`	✅	✅
`obj?.k` Optional Chaining Operator	✅	✅
`obj[k]` Dot Notation vs Bracket Notation	✅	✅
Reflect.get	✅	✅

Set

syntax	use proto chain	work with Symbol Key
`obj.k = v`	no	✅
`obj[k] = v`	no	✅
Reflect.set	no	✅

Delete

syntax	use proto chain	work with Symbol Key
delete (operator) ❌	no	✅
Reflect.deleteProperty	no	✅

Check Existence

syntax	use proto chain	work with Symbol Key
Object.hasOwn	no	✅
Object.prototype.hasOwnProperty ❌	no	✅
in (operator)	✅	✅
Reflect.has	✅	✅

List Properties

JS: List Properties

JavaScript. Access Properties

JavaScript. Property