Test your knowledge of Swift functionality by reading code and trying to predict the output.
Read randomly generated Swift code and try to figure out which line contains an error.
It's hard to know what you don't know, so how can you figure out what holes you have in your knowledge? Simple: take the final example from the 100 Days of Swift – it's a 100-question test that covers a vast range of Swift and iOS, and will identify your weak spots in under an hour.
Work your way through 100 tests about individual Swift topics – variadic functions, class inheritance, protocol extensions, and more.
Try your hand at 30 tests that cover the first 30 Hacking with Swift projects, including UIKit, SpriteKit, Core Graphics, and much more.
Your web browser automatically tracks which tests you've taken, so you can see how far you've come.
This page contains the largest collection of Swift and iOS tests in existence – thousands of questions in total, plus interview questions, skill assessments, and more. You might think that's nice enough, but there's a twist:
These questions are used by companies around the world in their own job interviews for iOS developers.
As the industry standard Swift tests, you can use these now to get ahead of the pack: in the run up to your next interview you can spend 10 minutes a day completing tests or answering questions here, and you can be sure the work will pay off.
All these tests are both free and anonymous, so there's nothing standing between you and acing your next interview – good luck!