Specifies the default value of the property with the specified key.
- iOS 2.0+
- macOS 10.5+
- Mac Catalyst 13.0+
- tvOS 9.0+
- Core Animation
The name of one of the receiver’s properties.
The default value for the named property. Returns
nil if no default value has been set.
If this method returns
nil a suitable “zero” default value for the property is provided, based on the declared type of the
key. For example, if
key is a
CGSize object, a size of (0.0,0.0) is returned. For a
CGRect an empty rectangle is returned. For
CATransform3D, the appropriate identity matrix is returned.
key is not a known for property of the class, the result of the method is undefined.