# init(validatingUTF8:) Creates a new string by copying and validating the null-terminated UTF-8 data referenced by the given pointer. ``` init?(validatingUTF8 cString: UnsafePointer) ``` ## Parameters `cString` A pointer to a null-terminated sequence of UTF-8 code units. ## Discussion This initializer does not try to repair ill-formed UTF-8 code unit sequences. If any are found, the result of the initializer is `nil`. The following example calls this initializer with pointers to the contents of two different `CChar` arrays—the first with well-formed UTF-8 code unit sequences and the second with an ill-formed sequence at the end. ``` let validUTF8: [CChar] = [67, 97, 102, -61, -87, 0] validUTF8.withUnsafeBufferPointer { ptr in let s = String(validatingUTF8: ptr.baseAddress!) print(s) } // Prints "Optional("Café")" let invalidUTF8: [CChar] = [67, 97, 102, -61, 0] invalidUTF8.withUnsafeBufferPointer { ptr in let s = String(validatingUTF8: ptr.baseAddress!) print(s) } // Prints "nil" ``` > Note: This initializer has been renamed. Use > `String.init?(validatingCString:)` instead. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)