learn-swift

A guidance project on using Swift from CS308 Programming Languages at Fulbright University Vietnam

General Information

Swift was created on December 3, 2015, by Apple in an attempt to replace the old-dying Objective-C for its application development purpose. However, in Stack Overflow's 2021 developer survey, only 5% of the community uses Swift regularly, which is a tiny percentage.

So, why learn Swift? If you are looking for an easy, interacting but powerful programming language, Swift is the right choice. Apple even advertises that anyone, even children having no experience with coding, can learn it. However, if you want to become an Apple developer, learning Swift is necessary.

Apple also creates a paired compiler to run Swift code called Xcode. You may find Xcode hard to use at first, but it will become much easier and more powerful when it continues being used. Additionally, SwiftUI, an UI development tool integrated into Xcode, is made in a way that runs and previews the code's result directly on an Apple device instead of a console or pop-up window like Python does.

There are many resources for developers who are investigating Swift, such as:

• The Swift programming language for a comprehensive language guide
• Swift Playground for interacting lessons on building apps using Swift
• Swift Documentation for detailed documentation
• Apple's GitHub for public source code

Getting Started

Let's get the ball rolling, aren't we? To code in Swift, you have to:

1. Have a Mac (Swift cannot be run from a Window or Linux device)
2. Have an Apple ID. If you have not created one, please visit Apple ID and click on Create Your Apple ID on the top right of the screen to create an Apple ID.
3. Install Xcode on your Mac (once again, Xcode is an Apple-developed compiler for Swift). On the site, you will find that there are 2 downloading options: Download from Website and Download from Mac App Store. For the beginner, I'd recommend you choose the latter (Download from Mac App Store) for convenience as it will install the newest version and all necessary tools. But if you want to choose the version (including both official and beta versions) of Xcode and manually install the additional tool, choose Download from Website. To be clear, the version I use for this tutorial is 13.2.1.¹
4. [optional] Clone this repository. The folder Demo Code provides many Swift codes shown in this guide for you to play around with. You may use Xcode to run the playground files. For instructions to preview code directly on Github, please refer to this section on Code Preview

Once you have done all steps, you are ready to begin.

¹ For more instructions on installing and running Xcode, please visit Apple Developer: Xcode.

Language Guide

This guide covers the following information on Swift:

1. The Basics
2. Constants and Variables
3. Basic Operators
4. Short-circuit Evaluation
5. Selection Statements
6. Iteration Statements
7. Control Transfer Statements
8. Functions
9. Recursions
10. Instances

If the hyperlinks do not work for you, the contents are located in folder language guide.

Demo Code

Above example codes are avaialable in the folder code.

In the case of code preview on GitHub, each .playground folder will have multiple .xcplaygroundpage sub-folders associated with different language guide sections. Open a sub-folder, and find a Content.swift file. Open it to preview the example codes. However, I still prefer you to clone this repository and run the .playground file with a compiler such as Xcode.

Programming project

This project is available at the showcase repository.

It's time to build our first Swift's program, an application for students to browse and read research articles. This idea originates from the UX project called Project Gallery from CS303 Human-Computer Interaction at Fulbright University Vietnam. However, we will not build the mobile app version of that interface. In fact, this app will have a different user interface. Therefore, it will be renamed Showcase to respect the authors.

Some basic features of Showcase:

• Article showcasing on a user-centric GUI
• Article recommendation based on the users' histories comparison algorithm
• Article interaction such as saved and flagged

Additionally, Showcase is a native-iOS app that supports:

• Color mode (light and dark) switching

On top of that, Showcase should also stores and fetchs data from the database, which adds these functions to the program:

• New article's updation
• Article searching by titles
• User's sign-in

That is all for the first version of our first app built with Swift. Below is a peak of what will our app look like (designed using Figma). If you are interested in this app, check this repo for the app's code and this repo for the app's dataset.

For a closer look, let's watch this Youtube video: Showcase App Preview.

References

Comi, M. (2016, April 20). Struct-style printing of classes in Swift. Medium. Retrieved April 18, 2022, from https://medium.com/swift-programming/struct-style-printing-of-classes-in-swift-7ee34f1c975a

Inc., A. (2022). The Swift Programming Language (Swift 5.6). Retrieved March 25, 2022, from https://docs.swift.org/swift-book

Overflow, S. (2021). 2021 Developer Survey. Stack Overflow. Retrieved March 26, 2022, from https://insights.stackoverflow.com/survey/2021#section-most-popular-technologies-programming-scripting-and-markup-languages

Swift functions. Programiz. (2022). Retrieved April 10, 2022, from https://www.programiz.com/swift-programming/functions

Veen, T. in't. (2019). Chapter 9. Iterators, sequences, and collections. In Swift in depth. Manning.