Type Method


Specifies the default value associated with the specified key.


class func defaultValue(forKey key: String) -> Any?



The name of one of the receiver’s properties.

Return Value

The default value for the named property. Returns nil if no default value has been set.


If you define custom properties for a layer but do not set a value, this method returns a suitable “zero” default value based on the expected value of the key. For example, if the value for key is a CGSize struct, the method returns a size struct containing (0.0,0.0) wrapped in an NSValue object. For a CGRect an empty rectangle is returned. For CGAffineTransform and CATransform3D, the appropriate identity matrix is returned.

Special Considerations

If key is not a known for property of the class, the result of the method is undefined.

See Also

Key-Value Coding Extensions

func shouldArchiveValue(forKey: String) -> Bool

Returns a Boolean indicating whether the value of the specified key should be archived.