Yesterday I got asked, what a Swift beginner should learn first. Here is the question:
I did want to ask you something, is it worth a while to learn TDD, or spend that time learning Swift, and functional programming?
Of course, my opinion is a bit biased as I wrote a book about TDD with Swift. So, keep that in mind when you read my answer.
Advice #1: Read the Swift Book provided by Apple.
In my opinion you should first learn Swift. This is the basis of everything. If you don’t understand what functions can do in Swift, you won’t understand the concepts of functional programming in Swift. In addition, Swift is still mainly used to write apps for iOS and OS X. This means, most of the time you need to interact with object oriented APIs (at least at the time of writing ;)). So you also need to understand object oriented Swift to leverage the potential of Swift when writing Swift.
And even if you don’t believe me, this is what Chris Eidhof, Florian Kugler, and Wouter Swierstra write in Functional Swift:
„You should be comfortable reading Swift programs and familiar with common programming concepts, such as classes, methods, and variables. If you’ve only just started to learn to program, this may not be the right book for you.“
Advice #2: Read a ton of blog posts. There are so many great Swift blogs.
The book by Apple is very good. But if you want to see what all those creative minds in the community come up with, you need to read many blogs.
Advice #3: Learn writing tests and use the knowledge to write tests for your code.
To me, legacy code is simply code without tests.
For me Test-Driven Development is good to start with tests because the question what to test is secondary. You (kind of) write tests for (nearly) everything. One of the rules in TDD is that you only write code if you have a failing test.
Advice #4: Learn functional programming.
Swift also has functional aspects. You don’t need to use them, but if you are (or willing to become) active in den community, you most probably will encounter functional magic soon. In my opinion, learning functional programming makes you a better developer. Often functional code looks like magic at first. It just works (which you can prove because you have tests).
This is my opinion. I am sure that there are many developer with different opinions. Go on, ask them what they think about it.
And, buy my book. ;)