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# CFNumberFormatterSetProperty(_:_:_:)

Sets a number formatter property using a key-value pair.

```
func CFNumberFormatterSetProperty(_ formatter: CFNumberFormatter!, _ key: CFNumberFormatterKey!, _ value: CFTypeRef!)
```

## Parameters

`formatter`

The number formatter to modify.

`key`

The name of the property of `formatter` to set. See [Number Formatter Property Keys](/documentation/CoreFoundation/number-formatter-property-keys) for a description of possible values.

`value`

The value of the specified key. This must be an instance of the correct `CFType` object for the corresponding key.

## Discussion

---

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