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# CFNumberFormatterCopyProperty(_:_:)

Returns a copy of a number formatter’s value for a given key.

```
func CFNumberFormatterCopyProperty(_ formatter: CFNumberFormatter!, _ key: CFNumberFormatterKey!) -> CFTypeRef!
```

## Parameters

`formatter`

The number formatter to examine.

`key`

A property key. See [Number Formatter Property Keys](/documentation/CoreFoundation/number-formatter-property-keys) for valid values.

## Return Value

A `CFType` object that is a copy of the property value for `key`. Returns `NULL` if there is no value specified for `key`. Ownership follows the [The Create Rule](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029).

## Discussion

---

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