---
title: identifier()
framework: quartz
role: symbol
role_heading: Instance Method
path: quartz/qccomposition/identifier()
---

# identifier()

Returns the unique and persistent identifier for the composition from the composition repository.

## Declaration

```swift
func identifier() -> String!
```

## Return Value

Return Value The unique identifier for the composition if it comes from the composition repository; nil otherwise.

## See Also

### Getting Information About a Composition

- [attributes()](quartz/qccomposition/attributes().md)
- [protocols()](quartz/qccomposition/protocols().md)