Creates a new integer value from the given string and radix.
SDK
- Xcode 9.0+
Framework
- Swift Standard Library
Declaration
init?<S>(_ text: S, radix: Int = 10) where S : StringParameters
textThe ASCII representation of a number in the radix passed as
radix.radixThe radix, or base, to use for converting
textto an integer value.radixmust be in the range2...36. The default is 10.
Discussion
The string passed as text may begin with a plus or minus sign character (+ or -), followed by one or more numeric digits (0-9) or letters (a-z or A-Z). Parsing of the string is case insensitive.
let x = Int("123")
// x == 123
let y = Int("-123", radix: 8)
// y == -83
let y = Int("+123", radix: 8)
// y == +83
let z = Int("07b", radix: 16)
// z == 123
If text is in an invalid format or contains characters that are out of bounds for the given radix, or if the value it denotes in the given radix 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("zzzzzzzzzzzzz", radix: 36) // Out of range