Swift Tour Essay summary (2)

Type Aliases

typealias AudioSample = UInt16
Booleans

Non-boolean values are not replaced by bool, for example:

let i = 1
if i {
// this example will not compile, and will report an error
}
Tuples

Example: HTTPStatus Code ("404", "Not Found")

let http404Error = (404, "Not Found")
// http404Error is of type (Int, String)
Access Tuple:

let (statusCode, statusMessage) = heep404Error
println ("This status code is \ (statusCode)")
// prints "The status code is 404"
println ("The statuis message is \ (statusMessage)")
// prints "The status message is Not Found"
Shorthand, use _ instead of unnecessary variables, for example:

let (justTheStatusCode, _) = http404Error
println ("The status code is \ (justTheStatusCode)")
// prints "The status code is 404"
Another access tuple method:

println ("The status code is \ (http404Error.0)")
// prints "The status code is 404"
println ("The status message is \ (http404Error.1)")
// prints "The status message is Not Found"
Tuple's complete definition

let http200Status = (statusCode: 200, description: "OK")
Corresponding access

println ("The status code is \ (http200status.statusCode)")
println ("The status code message is \ (http200status.description)")
Swift Tour Essay Summary (2)