In this edition: the 100 Days of SwiftUI is getting a massive update for iOS 17, a new book is in the works, a return to functional programming, and more.

Updating the 100 Days of SwiftUI

Today I started the process of updating the 100 Days of SwiftUI for iOS 17 and SwiftData. This will mean updating almost every project to use all the changes introduced since the last major update, but I’m also taking this chance to simplify the course and add extra detail where possible – I want this to be the best edition yet, and of course it will remain completely free.

I’d love to have your help here. If you went through the 100 Days of SwiftUI course in the least year or two, were there parts you found particularly difficult, or some concepts that needed extra explanation? If so, please email me with your feedback so I can improve this for the iOS 17 version update. Thank you!

Note: If you're currently following the 100 Days curriculum, I recommend you keep going. The first updates ought to land about a week after the final release of iOS 17, and will be rolled out gradually from then, so if you plan to start after September 1st I'd suggest you wait until the updated days appear.

Get ready for SwiftData by Example!

It’s been a while since I launched a new book, so I’m really pleased to announce SwiftData by Example is coming next month!

You might have noticed I haven’t written anything about SwiftData so far, which is intentional – it was clear the API was going to change massively, and also I wanted to make sure I had enough experience of it in practical code, so I could be sure I was sharing the best tips and techniques I can.

Well, I’ve slowly been collating all my notes, conducting experiments, building sample projects, and asking as many questions as I can, and finally all that effort is almost ready to share.

If you follow my work closely you’ll know how strongly I believe in giving away as much as I can. So, I’m really pleased to say that SwiftData by Example will be following my previous books SwiftUI by Example and Swift Concurrency by Example: it will be available to buy in a download edition, or available online to read completely free of charge.

Watch this space!

Thanks to sponsors

I’m grateful to the four sponsors who supported Hacking with Swift last month:

RevenueCat makes in-app subscriptions straightforward and reliable so you can get back to building your app. Find out more.
Essential Developer are running a series of free crash courses for mid/senior iOS devs who want to take their skills to the next level. Find out more.
TelemetryDeck is a lightweight analytics platform for your app that doesn’t compromise user privacy. Find out more.
WishKit is an easy to use SDK that allows users to create and upvote features in your app. Sign up for free! Find out more.

My favorite SwiftUI feature from iOS 17

I uploaded a new YouTube Short covering my favorite SwiftUI feature from iOS 17: using symbol effects to animate SF Symbols in all sorts of beautiful ways. I know this took the Apple teams a lot of time to get right, but for us it’s just one line of code to get really great results – and I just love the simple, expressive API.

The video is only a minute long – watch it here.

News from friends

Daniel Steinberg started a YouTube channel a few months ago, and having watched some of his work I know how much time and care he puts into every video he uploads.

Recently he’s been creating videos about the new observation system introduced in iOS 17, and honestly I can’t think of a better way to really get to grips with how it all works – he makes sure to pull back the curtain and show why things work the way they do, rather than just showing lots of code.

Anyway, I encourage you to watch them for yourselves, and if you enjoy them please do hit the like button on YouTube so that other folks can find them too!

Part 1: https://www.youtube.com/watch?v=vyJHz2J69ZA
Part 2: https://www.youtube.com/watch?v=3lRFnDBzsS0
Part 3: https://www.youtube.com/watch?v=XufaUTL-m6U
Part 4: https://www.youtube.com/watch?v=KNcCh1uq-OU

Back to functional programming

I’ve finally found time to return to the Hacking with Swift+ on functional programming. The series has already covered the importance of pure functions, how to use functions as first-class types, and using map(), compactMap(), and filter(). Well, the latest video talks about using the reduce() function to boil lots of data down to a single value – it’s used more often than you might think!

More videos in this series will becoming soon, but in the meantime you can find the latest video here.

Discounts on books

Here's a reminder of the supporter's discount codes you can use to save money on all my books:

Pro SwiftUI: https://gum.co/pro-swiftui/hws-thankyou
Pro Swift: https://gum.co/proswift/hws-thankyou
SwiftUI By Example: https://gum.co/swiftui/hws-thankyou
Swift Concurrency By Example: https://gum.co/concurrency/hws-thankyou
Hacking with iOS: https://gum.co/hws-book-pack/hws-thankyou
Swift Design Patterns: https://gum.co/swift-design-patterns/hws-thankyou
Testing Swift: https://gum.co/testing-swift/hws-thankyou
Swift on Sundays Volume One: https://gum.co/swift-on-sundays-1/hws-thankyou
Advanced iOS Volume One: https://gum.co/advanced-ios-1/hws-thankyou
Advanced iOS Volume Two: https://gum.co/advanced-ios-2/hws-thankyou
Advanced iOS Volume Three: https://gum.co/advanced-ios-3/hws-thankyou
Swift Coding Challenges: https://gum.co/swiftcc/hws-thankyou
Dive Into SpriteKit: https://gum.co/dive-into-spritekit/hws-thankyou
Hacking with macOS: https://gum.co/hwmacos/hws-thankyou
Hacking with watchOS: https://gum.co/hwwatchos/hws-thankyou
Hacking with tvOS: https://gum.co/hwtvos/hws-thankyou
Hacking with Swift Live Series 1: https://gum.co/hws-live-1/hws-thankyou
Objective-C for Swift Developers: https://gum.co/objcswift/hws-thankyou
Beyond Code: https://gum.co/beyondcode/hws-thankyou

Remember, if you already bought books from either the Swift Power Pack, the Swift Platform Pack, or the Swift Plus Pack and want to upgrade to the full bundle, I can create a custom discount code for you that takes off whatever you already paid – just email me.

One more thing…

I got back from my summer vacation yesterday, and have a mountain of emails waiting for me. As you’ve read above, I’ll also be editing a new, free book on SwiftData, starting the epic work of updating the 100 Days of SwiftUI, and also working on some new enhancements for Hacking with Swift+, so I hope you can see I have a rather busy month ahead – I really appreciate your patience while I get around to answering all your messages!

I know having a long summer break is a classic stereotype of Europeans, but I really do feel energized and ready to go afterwards. The build-up to WWDC, then the big week itself, then running Hacking with Swift Live shortly afterwards all takes a heavy toll, so being able to pause work for a while helps reset my brain.

But the long break also gave me a lot of chance to refocus on all the free work I do – free books, and free tutorials that help thousands of people take their first steps towards a new career. In fact, in May this year I reached a major milestone: 100,000 people completed the 100 Days of SwiftUI, which just blows my mind.

A few months ago I conducted a poll with a random selection of Hacking with Swift+ subscribers, asking them why they subscribed. I had a range of responses:

8 people said they wanted to learn advanced techniques
4 people said they asked their company to get a team license
3 people said they wanted the exclusive gifts
5 people said they wanted to support my free work

The last one really hit me hard – people saying they already had a great job and found themselves using my site often, so they wanted me to help others; they wanted to pay it forward, so others could learn too.

I work as hard as I can to give away as much as I can so that everyone in our community can benefit, but ultimately I wouldn’t be able to do a tenth of what I do without your support, and for that I’ll always be grateful – thank you!

Paul

Hacking with Swift Newsletter: April 2025

Hacking with Swift Newsletter: March 2025

Hacking with Swift Newsletter: February 2025

Hacking with Swift Newsletter: January 2025

Hacking with Swift Newsletter: December 2024

See all posts from Paul Hudson