First impression of Swift (Apple’s new programming language)

Swift is Apple’s new programming language, which promises to allow you to write iOS and OS X apps more easily than with Objective-C. Apple have released a free eBook titled “The Swift Programming Language” which provides an overview of the language. This is where I gained my main impressions on Swift. To give you a little background on myself: while I have had an interest in getting into app development for a while, at this point I haven’t touched any Objective-C – I am currently programming mainly with C, C++ and Python.

The first thing I thought when I started looking at the Swift code examples, is how much it reminds me of Python. Consider the first Python script most of us learned:

print("Hello, world!")

Now consider Swift’s syntax:

println("Hello, world")

At the same time, the method for assigning variables reminds me very much of the syntax of Javascript. To assign a variable in Swift:

var mynumber = 23

However, defining constants seems a little weird to me, as you have to use the keyword “let” rather than “var”:

let pi = 3.14

Swift will automatically work out that the constant “pi” is a float, although it does give you ways to explicitly define the type, especially if you want the precision of a double.

Next, moving onto arrays, the resemblance to Python is uncanny, to take the example that Apple have used in their book:

var shoppingList = ["catfish", "water", "tulips", "blue paint"]
shoppingList[1] = "bottle of water"

Control flow and loops employ a very C-like syntax, although the braces again make the code appear similar to JavaScript. To take another code example from the book:

let individualScores = [75, 43, 103, 87, 12]
var teamScore = 0
for score in individualScores {
    if score > 50 {
        teamScore += 3
    } else {
        teamScore += 1
    }
}

I’ve only scratched the surface of Swift in this short post, and if you’re interested in app development I’d recommend downloading the free eBook and having a browse through. I was rather put off getting into App development by how busy I was and by the syntax of Objective-C. I really like how Scratch looks and think when Xcode 6 is released I might finally be motived to build a native iOS app.