A value type whose instances are either
- Xcode 6.0.1+
- Swift Standard Library
Bool represents Boolean values in Swift. Create instances of
Bool by using one of the Boolean literals
false, or by assigning the result of a Boolean method or operation to a variable or constant.
Swift uses only simple Boolean values in conditional contexts to help avoid accidental programming errors and to help maintain the clarity of each control statement. Unlike in other programming languages, in Swift, integers and strings cannot be used where a Boolean value is required.
For example, the following code sample does not compile, because it attempts to use the integer
i in a logical context:
The correct approach in Swift is to compare the
i value with zero in the
Using Imported Boolean values
Boolean types and the Objective-C
BOOL type are all bridged into Swift as
Bool. The single
Bool type in Swift guarantees that functions, methods, and properties imported from C and Objective-C have a consistent type interface.