Jacobs - The Missing Manual for Swift Development

Developers that come to Apples platforms have many different backgrounds, and some of us are better prepared than others. Regardless of your background, though, you can make sure that youre a good fit for Apples ecosystem by investing in your foundation. Thats the subject of this chapter.

This may sound boring at first, and for some it is boring, but its essential if you plan to create robust, scalable applications and if you want to have a long career in the mobile space.

Theres a slew of reasons why developers are drawn to Apples ecosystem. Many of us make the jump because of the shiny stuff. ARKit and Core ML are good examples of what I like to refer to as shiny stuff. Both are amazing technologies, and Im sure youve seen stunning examples of developers taking advantage of ARKit. ARKit and Core ML are the cherries on the cake. And the cake is your foundation. Without the cake, there are no cherries.

The foundation is what happens to interest me most. It isnt as compelling or visually stunning as ARKit, but its essential for every single application. Not only is that why its so important, but thats also why its worth investing time in your foundation. It pays dividends for a long time. Lets start with the language.

As a Swift developer, the first component of your foundation should be the language you use day in day out. Swift. Since youre reading this, Im going to assume that you already have a good grasp of the Swift language or, at a minimum, youve browsed The Swift Programming Language and youve written a handful of lines in a playground.

Im sure I dont need to convince you of the importance of knowing and understanding the Swift language. How are you going to write a fantastic novel if you dont master the language the novel is written in? Why would this be any different for software development?

But this doesnt mean you need to spend days, weeks, or months learning the Swift language. I recommend a different approach thats more fun and more practical. I dont like spending hours or days learning a new library, framework, or API. I learn best by applying what I read and learn. The same is true for the Swift language.

Start with the basics and use it. You can pick up the basics of any language in no time. But, as with any language, you only get what youve learned by applying it. That means writing Swift. You can use Swift in a playground or start with a simple Cocoa application. Apple did a fantastic job by introducing playgrounds alongside the unveiling of the Swift language. Use them. Launch Xcode, create a playground, and play with Swift.

Many developers will go through a phase in which they struggle with the language. Thats fine. Let yourself be frustrated for a while. Its natural, and it means that youre noticing aspects of Swift that are core to the language. Be skeptical and ask questions.

Based on conversations with students and readers, optionals are one of the most common obstacles developers need to overcome. I genuinely love optionals, but I too was frustrated when they first crossed my path. This wasnt surprising considering my background in Objective-C. As you probably know, Objective-C isnt as strict about nil pointers. Dealing with nil is an entirely different story when youre writing Swift.

If youre still struggling with optionals or dont see how they fit in the language, then I need to ask you to trust the language for now. It will click at some point, but you need to embrace optionals. Dont use the exclamation mark to plow your way through a forest of optionals. Optionals are an integral part of the language and an essential component of one of Swifts key features, safety.

The more you use the language, the more you start to appreciate it. What I tend to do is gradually add more complexity to the code I write. Learn about value types and reference types. Discover what protocols are and why theyre useful. You may want to explore generics at some point. Take a close look at enumerations and find out why theyre so much more powerful than their Objective-C counterparts.

If you think you know the Swift language, then I recommend taking another look at The Swift Programming Language . Every time I read Apples guide, I learn something new. Most of the times, I can directly apply it to the code I write day to day. I love it. Swift was designed to be more expressive, and it feels richer than Objective-C. Thats something you can and should take advantage of in the code you write.