# init(_:) Creates a new integer value from the given string. ``` init?(_ description: String) ``` ## Parameters `description` The ASCII representation of a number. ## Discussion The string passed as `description` may begin with a plus or minus sign character (`+` or `-`), followed by one or more numeric digits (`0-9`). ``` let x = Int("123") // x == 123 ``` If `description` is in an invalid format, or if the value it denotes in base 10 is not representable, the result is `nil`. For example, the following conversions result in `nil`: ``` Int(" 100") // Includes whitespace Int("21-50") // Invalid format Int("ff6600") // Characters out of bounds Int("10000000000000000000000000") // Out of range ``` --- 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)