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# async(group:qos:flags:execute:)

Schedules a block asynchronously for execution and optionally associates it with a dispatch group.

```
@preconcurrency func async(group: DispatchGroup? = nil, qos: DispatchQoS = .unspecified, flags: DispatchWorkItemFlags = [], execute work: @escaping @Sendable () -> Void)
```

## Parameters

`group`

The dispatch group to associate with the work item. If you specify `NULL`, the block is not associated with a group.

`qos`

The quality-of-service class to use when executing the block. This parameter determines the priority with which the block is scheduled and executed. For a list of possible values, see [`DispatchQoS`](/documentation/Dispatch/DispatchQoS).

`flags`

Additional attributes to apply when executing the block. For a list of possible values, see [`DispatchWorkItemFlags`](/documentation/Dispatch/DispatchWorkItemFlags).

`work`

The block containing the work to perform. This block has no return value and no parameters.

## Discussion

---

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