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# metadata

Metadata about the units and other properties of the characteristic.

```
var metadata: HMCharacteristicMetadata? { get }
```

## Discussion

You can typically infer a lot about a characteristic’s [`value`](/documentation/HomeKit/HMCharacteristic/value) from its [`characteristicType`](/documentation/HomeKit/HMCharacteristic/characteristicType), like if the value is a string, a number, or in some other format; what the units are; and what range of values to expect. To obtain this information explicitly, inspect the characteristic’s [`metadata`](/documentation/HomeKit/HMCharacteristic/metadata), represented by an instance of the [`HMCharacteristicMetadata`](/documentation/HomeKit/HMCharacteristicMetadata) class.

---

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