Contents

defaultValue(forKey:)

Specifies the default value of the property with the specified key.

Declaration

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

Parameters

  • key:

    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.

Discussion

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 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.