---
title: "init(predicate:)"
framework: healthkit
role: symbol
role_heading: Initializer
path: "healthkit/hksourcequerydescriptor/init(predicate:)"
---

# init(predicate:)

Creates a source query descriptor.

## Declaration

```swift
init(predicate: HKSamplePredicate<Sample>)
```

## Parameters

- `predicate`: A predicate that defines the set of data used to identify sources. For a list of convenience methods for building predicates, see doc://com.apple.healthkit/documentation/HealthKit/HKQuery.