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# lengthOfBytes(using:)

Returns the number of bytes required to store the receiver in a given encoding.

```
func lengthOfBytes(using enc: UInt) -> Int
```

## Parameters

`enc`

The encoding for which to determine the receiver’s length.

## Return Value

The number of bytes required to store the receiver in the encoding `enc` in a non-external representation. The length does not include space for a terminating `NULL` character. Returns `0` if the specified encoding cannot be used to convert the receiver or if the amount of memory required for storing the results of the encoding conversion would exceed <doc://com.apple.documentation/documentation/ObjectiveC/NSIntegerMax>.

## Discussion

The result is exact and is returned in `O(n)` time.

---

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