Enough for the background and history. Let's begin to look into Swift.
To get a taste of Swift programming language, let's take a look at the following code snippets.
Objective-C
Swift
The first block of code was written in Objective-C, while the second one was written in Swift. Which language do you prefer? I guess you would prefer to program in Swift, especially if you're frustrated with the Objective-C syntax. It's clearer and readable. There is no @ sign and semi-colon at the end of each statement. Both statements below concatenate the first and second messages together. I believe you can probably guess the meaning of the following Swift code:
but find it a bit confusing for the Objective-C code below:
Chapter 2
Your First Taste of Swift with Playgrounds
Now that you have configured everything you need to start iOS app development, let me answer another common question from beginners before moving on. A lot of people have asked me about what skills you need in order to develop an iOS app. In brief, it comes down to three areas:
Learn Swift - Swift is now the recommended programming language for writing iOS apps.
Learn Xcode - Xcode is the development tool for you to design the app UI, write Swift code, and build your apps.
Understand the iOS software development kit - Apple provides the software development kit for developers to make our lives simpler. This kit comes with a set of software tools and APIs that empowers you to develop iOS apps. For example, if you want to display a web page in your app, the SDK provides a built-in browser that lets you embed right in your application.
You will have to equip yourself with knowledge on the above three areas. That's a lot of stuff. But no worries. You'll learn the skills as you read through the book.
Let me start off by telling you a bit about the history of Swift.
In the Worldwide Developer Conference 2014, Apple surprised all iOS developers by launching a new programming language called Swift. Swift is advertised as a "fast, modern, safe, interactive" programming language. The language is easier to learn and comes with features to make programming more productive.
Prior to the announcement of Swift, iOS apps were primarily written in Objective-C. The language has been around for more than 20 years and was chosen by Apple as the primary programming language for Mac and iOS development. I've talked to many aspiring iOS developers. A majority of them said Objective-C was hard to learn and its syntax looked weird. Simply put, the code scares some beginners off from learning iOS programming.
The release of Swift programming language is probably Apple's answer to some of these comments. The syntax is much cleaner and easier to read. I have been programming in Swift since its beta release. It's more than 4 years for now. I can say you're almost guaranteed to be more productive using Swift. It definitely speeds up the development process. Once you get used to Swift programming, it would be really hard for you to switch back to Objective-C.
It seems to me that Swift will lure more web developers or even novice to build apps. If you're a web developer with some programming experience on any scripting languages, you can leverage your existing expertise to gain knowledge on developing iOS apps. It would be fairly easy for you to pick up Swift. Being that said, even if you're a total beginner with no prior programming experience, you'll also find the language friendlier and feel more comfortable to develop apps in Swift.
In June 2015, Apple announced Swift 2, and that the programming language goes open source. This is a huge deal. Since then, developers created some interesting and amazing open source projects using the language. Not only can you use Swift to develop iOS apps, companies like IBM developed web frameworks for you to create web apps in Swift. Now you can run Swift on Linux too.
Following the release of Swift 2, Apple introduced Swift 3 in June 2016. This version of the programming language, integrated into Xcode 8, was released in Sep, 2016. This was considered as one of the biggest releases since the birth of the language. There were tons of changes in Swift 3. APIs are renamed and more features were introduced. All these changes helped to make the language even better and enabled developers to write more beautiful code. That said, it took all developers extra efforts to migrate their projects for these breaking changes.
In June 2017, Apple brought you Swift 4, along with the release of Xcode 9, with even more enhancements and improvements. This version of Swift had a focus on backward compatibility. That meant ideally projects developed in Swift 3 could be run on Xcode 9 without any changes. Even if you had to make changes, the migration from Swift 3 to 4 would be much less cumbersome than that from 2.2 to 3.
This year, Apple only releases a minor update for Swift, pushing Swift's version number to 4.2. Even though it's not a major release, the new version also comes with a lot of language features to improve productivity and efficiency. You may wonder if Apple is slowing down the development of Swift by just releasing a minor update. Actually, it's a good news for aspiring developers. In some ways, this means the Swift language becomes more stable and mature.
If you're a total beginner, you may have a couple of questions in mind. Why does Swift keep changing? If it keeps updating, is Swift ready for use?
Nearly all programming languages change over time. The same is for Swift. New language features are added to Swift every year to make it more powerful and developer friendly. It is somewhat similar to our spoken languages. Let's say, for English, it still changes over time. New vocabulary and phrases such as freemium are added to the dictionary every year.
All languages change over time, and there can be many different reasons for this. The English language is no different.
While Swift keeps evolving, it doesn't mean it is not ready for production use. Instead, if you are going to build an iOS app, you should build it in Swift. It has become a de facto standard for iOS app development. Companies such as LinkedIn, Duolingo and Mozilla had already written apps entirely in Swift since its early versions. Since the release of Swift 4, the programming language is more stable, and definitely ready for enterprises and production uses.
That's all for the introduction. Take some time to install Xcode on your Mac, and come up with your own app idea. Even though I may not teach you to build the exact same app, you will learn the coding techniques that empower you to build your own app.
When you proceed to the next chapter, we will start programming in Swift.
