# init(_:radix:uppercase:) Creates a string representing the given value in base 10, or some other specified base. ``` init(_ value: T, radix: Int = 10, uppercase: Bool = false) where T : BinaryInteger ``` ## Parameters `value` The value to convert to a string. `radix` The base to use for the string representation. `radix` must be at least 2 and at most 36. The default is 10. `uppercase` Pass `true` to use uppercase letters to represent numerals greater than 9, or `false` to use lowercase letters. The default is `false`. ## Discussion The following example converts the maximal `Int` value to a string and prints its length: ``` let max = String(Int.max) print("\(max) has \(max.count) digits.") // Prints "9223372036854775807 has 19 digits." ``` Numerals greater than 9 are represented as Roman letters. These letters start with `"A"` if `uppercase` is `true`; otherwise, with `"a"`. ``` let v = 999_999 print(String(v, radix: 2)) // Prints "11110100001000111111" print(String(v, radix: 16)) // Prints "f423f" print(String(v, radix: 16, uppercase: true)) // Prints "F423F" ``` --- 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)