FREE TRIAL: Accelerate your app development career with Hacking with Swift+! >>

iExpense: Wrap up

Paul Hudson    @twostraws   

Although the app we were building wasn’t itself difficult, getting there took quite a bit of learning – we had to cover UserDefaults, Codable, sheet(), onDelete(), @ObservedObject, and more. Some of those things – particularly UserDefaults and Codable – have only been introduced at a high level in this project, which is intentional; we’ll be getting into them more later on.

Now that your SwiftUI skills are coming along, I hope you noticed we were able to skip past some parts with very little explanation. For example, you know very well how to create forms with text fields and pickers because we’ve already covered that extensively, which means we can spend our time focusing on new stuff.

Review what you learned

Anyone can sit through a tutorial, but it takes actual work to remember what was taught. It’s my job to make sure you take as much from these tutorials as possible, so I’ve prepared a short review to help you check your learning.

Click here to review what you learned in this project.


One of the best ways to learn is to write your own code as often as possible, so here are three ways you should try extending this app to make sure you fully understand what’s going on.

  1. Add an Edit/Done button to ContentView so users can delete rows more easily.
  2. Modify the expense amounts in ContentView to contain some styling depending on their value – expenses under $10 should have one style, expenses under $100 another, and expenses over $100 a third style. What those styles are depend on you.
  3. Add some validation to the Save button in AddView. If you enter “fish” or another thing that can’t be converted to an integer, show an alert telling users what the problem is.
Hacking with Swift is sponsored by Essential Developer

SPONSORED Join a FREE crash course for iOS devs who want to become complete senior developers — from October 18th to 24th. Learn how to apply iOS app architecture patterns through a series of lectures and practical coding sessions.

Learn more

Sponsor Hacking with Swift and reach the world's largest Swift community!

Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.6/5

Unknown user

You are not logged in

Log in or create account

Link copied to your pasteboard.