---
title: identifier
framework: xctest
role: symbol
role_heading: Instance Property
path: xctest/xctperformancemeasurement/identifier
---

# identifier

A unique identifier for a measurement.

## Declaration

```swift
var identifier: String { get }
```

## Discussion

Discussion Make an identifier for a measurement unique to the property being measured; it doesn’t need to be unique for each instance of a measurement. As an example, a measurement of database access performance might have the identifier com.example.ourdb_transactionthroughput.

## See Also

### Identifying Measurements

- [displayName](xctest/xctperformancemeasurement/displayname.md)