---
title: identifier
framework: healthkit
role: symbol
role_heading: Instance Property
path: healthkit/hkobjecttype/identifier
---

# identifier

A unique string identifying the HealthKit object type.

## Declaration

```swift
var identifier: String { get }
```

## Discussion

Discussion Each object type has a unique identifier. The identifiers can be grouped into different categories: HKQuantityTypeIdentifier, HKCategoryTypeIdentifier, HKCharacteristicTypeIdentifier, HKCorrelationTypeIdentifier, and HKDocumentTypeIdentifier Each group of identifiers is associated with a different concrete subclass of HKObjectType.

## See Also

### Getting property data

- [requiresPerObjectAuthorization()](healthkit/hkobjecttype/requiresperobjectauthorization().md)