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Wrap up

Debugging is a unique and essential skill that’s similar but different to regular coding. As you’ve just seen, there are lots of options to choose from, and you will – I promise! – use all of them at some point. Yes, even print().

There's more to learn about debugging, such as the Step Into and Step Out commands, but realistically you need to start with what you have before you venture any further. I would much rather you mastered three of the debugging tools available to you rather than having a weak grasp of all of them.

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 project 18.


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 your new knowledge to make sure you fully understand what’s going on:

  1. Temporarily try adding an exception breakpoint to project 1, then changing the call to instantiateViewController() so that it uses the storyboard identifier “Bad” – this will fail, but your exception breakpoint should catch it.
  2. In project 1, add a call to assert() in the viewDidLoad() method of DetailViewController.swift, checking that selectedImage always has a value.
  3. Go back to project 5, and try adding a conditional breakpoint to the start of the submit() method that pauses only if the user submits a word with six or more letters.
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Share your success!

One of the most effective motivators of success is sharing your progress with other people – when you tell folks what you're doing and what you've learned, it encourages you to come back for more, which in turn will help you reach your app development goals faster.

So, now that you've done all the hard work it's time to share your success: tell folks that you've completed this project, either by clicking the button below to start composing a tweet, or by writing your own message from scratch. This will definitely encourage you to keep learning, but it will also help other folks discover my work – thank you!


Buy Pro Swift Buy Pro SwiftUI 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 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 Beyond Code

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