JavaScript in Depth
JavaScript: Check Property Existence
By Xah Lee. Date:
2013-11-19
. Last updated:
2019-05-01
.
Check If a Object Has Own Property
Object.prototype.hasOwnProperty
Check If a Property is in Prototype Chain
Reflect.has
βinβ Operator
JavaScript Property
Property Overview
Property Key
Dot vs Bracket Notation
Create/Delete Property
Get/Set Property
Property Existence
Access Property
List Properties
for-in Loop
Enumerable
Property Attributes
Property Descriptor
Getter/Setter
BUY
Ξ£JS
JavaScript in Depth
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Property
Property Overview
Property Key
Dot vs Bracket Notation
Create/Delete Property
Get/Set Property
Property Existence
Access Property
List Properties
for-in Loop
Property Attributes
Getter/Setter
Property Descriptor
Symbol
Object and Inheritance
Object Overview
Object Type
Find Object's Type
Prototype and Inheritance
Prototype Chain
in Prototype Chain?
Get/Set Parent
Show Parent Chain π
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Object Literal Expr
Create Object + Parent
Prevent Adding Property
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