A type that represents data that does not typically change over time.
- iOS 8.0+
- Mac Catalyst 13.0+Beta
- watchOS 2.0+
HKCharacteristicType class is a concrete subclass of the
HKObjectType class. To create a characteristic type instance, use the object type’s
characteristicType(forIdentifier:) convenience method.
Unlike the other object types, characteristic types cannot be used to create and save new HealthKit objects. Instead, users must enter and edit their characteristic data using the Health app. Similarly, you cannot create queries for characteristic types. Instead, use the HealthKit store to access the data (see Reading Characteristic Data).
HealthKit provides five characteristic types: biological sex, blood type, birthdate, Fitzpatrick skin type, and wheelchair use. These types are used only when asking for permission to read data from the HealthKit store.
A type that identifies samples that contain a value from a small set of possible values.
The abstract superclass for all classes that identify a specific type of data when working with the HealthKit store.
An abstract superclass for all classes that identify a specific type of sample when working with the HealthKit store.
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