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# init(_:)

Creates a quantity type using the provided identifier.

```
convenience init(_ identifier: HKQuantityTypeIdentifier)
```

## Parameters

`identifier`

An identifier that specifies the type of data to store in the sample. For a complete list of quantity type identifiers, see [`HKQuantityTypeIdentifier`](/documentation/HealthKit/HKQuantityTypeIdentifier).

## Discussion

---

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