---
title: "readAttributeInt64u(completion:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrbaseclusterunittesting/readattributeint64u(completion:)"
---

# readAttributeInt64u(completion:)

## Declaration

```swift
func readAttributeInt64u(completion: @escaping @Sendable (NSNumber?, (any Error)?) -> Void)
```

```swift
func readAttributeInt64u() async throws -> NSNumber
```