iPhone,  Mac OS X,  Swift

Hello Swift

Let’s do a typical Hello World example in Swift. I have Xcode installed, so I can invoke a swift environment using xcrun, a command to start an interactive Xcode environment and then defining swift as the language I want to use, as follows using a standard Mac terminal session:

$xcrun swift

Then I get a welcome screen, which is kind:

Welcome to Apple Swift version 2.1.1 (swiftlang-700.1.101.15 clang-700.1.81). Type :help for assistance.

Then, I can throw some string into a variable:

1> let mystring = "Hello Swift"

And I get a response that the string was accepted, as a string:

mastering: String = "Hello Swift"

Then I can just echo that string out, popping it into a quoted and parenthetical (since it has a variable inside it, made regular by the \):

2> print ("mystring is \(mystring).")

And I get the following response:

mastering is Hello Swift.

Pretty simple syntax. We can also use two strings and then use the + operator to concatenate (a typical programming task):

let firstword = "Hello"
let secondword = "Swift"
let mystring = firstword + secondword
print ("mystring is \(mystring).")

Now that the basics are out of the way, why not build a Swift API…