Returns a Boolean that indicates whether the value specified by a given pointer is valid for the property identified by a given key.
- iOS 2.0+
- macOS 10.3+
- tvOS 9.0+
- watchOS 2.0+
A pointer to a new value for the property identified by
in. This method may modify or replace the value in order to make it valid.
The name of one of the receiver's properties. The key must specify an attribute or a to-one relationship.
If validation is necessary and
iois not transformed into a valid value, upon return contains an
NSErrorobject that describes the reason that
iois not a valid value.
A Boolean set to
YES if the value pointed at by
io is valid for the property identified by
in, or if the method is able to modify the value at
io to make it valid; otherwise
The default implementation of this method searches the class of the receiver for a validation method whose name matches the pattern
:. If you define such a method for a property, the default implementation of
validatecalls it when asked to validate the corresponding property, allowing your method to alter the input value if needed, and to determine the return value.
Value: for Key: error:
If no such method exists for a particular property,
YES. In other words, by default, the general validation call succeeds if you don't explicitly provide a validation method for the given property.