Answer 5 questions to help me learn how code.

The full gig is basically as follows. I am working on a very intricate application but I want to learn the actual code used and what the functions do so that if in the future I need to code anything similar I know exactly what it is and why I am doing it. I have above basic knowledge in the software language Swift which is what I am working with currently. These 5 questions will be in relation to this code language and will be completely random. This isn't simply me asking the 5 questions outright. They kind of come as I progress with my current project. The project is about 70% done and now I am just working on the functional coding specifically dealing with parsing and displaying the parsed data and doing value checks on the data to make sure that the correct info is displayed. I promise that the questions won't go longer than 2 weeks at most and this is a laid back project and if you can't wait the two weeks for me to mark it complete than this isn't for you.