Coding Explorer Blog

Functions in Swift: Parameters and Return Types

Last updated on August 10, 2020

I think we’ve gone over the basics of variables in Swift enough. It is time to talk about functions in Swift. Now, we have talked about these to some extent before, and I took it as a given that people would understand a bit. But now I think it is time to actually start diving in and explaining more specifics.

Functions are blocks of code that perform a task. You can then call these functions at different places, which makes fixing bugs much easier than the alternative. If you just copied and pasted the code everywhere, and you found a bug, you would have to change each one to fix that bug. With functions, you just change it one place, and everything that calls it gets the new fixed version of that block of code. The entire app itself is wrapped within a function called “main”, but you don’t normally interact with it, unless there’s a crash. Functions usually take arguments, and very often return data back to where it was called from.
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PregTracker 1.0.1 Released!

Last updated on July 26, 2014

I did not really mention it much online, but my wife became pregnant in the fall of 2013. Every time somebody would ask me “how far along is she?” I would have to stop and think, do some mental math, and eventually tell them the answer. I figured there had to be a better way.

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Access Control in Swift

Last updated on August 10, 2020

The access control in Swift is much more like the access control I am accustomed to in other languages like C# or Java, and I am quite thankful for that. I’m not saying there is anything wrong with Objective-C’s way of doing it, while it was different, I did like having the private properties in the interface block of the implementation (.m) file, and the public properties and methods in the header (.h) file. It made it easy to know exactly where to look.

Nonetheless, access control is here in Swift, so here we go. You can set access control to many things in Swift, particularly properties and methods, but you can even set it to types, initializers, subscripts, or protocols. Swift currently has three levels of access control:

Public
Internal
Fileprivate
Private

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Optional Chaining and Implicitly Unwrapped Optionals in Swift

Last updated on August 10, 2020

As promised last time, here is part two of my post about Swift optionals. Here we will discuss a few more advanced aspects on how to deal with optionals, optional chaining and implicitly unwrapped optionals. These are a few more tricks to get values out of optionals, while keeping Swift code much cleaner than its predecessors. Optional chaining makes it easy to drill into multiple levels of optional values. Implicitly unwrapped optionals, while not as safe as normal optionals, are often used under the assumption that the value that it is describing is never, or usually not, nil.

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Swift Optionals – Declaration, Unwrapping, and Binding

Last updated on August 10, 2020

Continuing our conversations about variables in Swift, lets move on to one of the more important additions in this realm to Swift, Optionals. In Swift, all normal variables must have a value. In Objective-C, C-based variables (primitives) always had to have a value, but object types could either be a valid object, or a pointer to nil. Swift optionals allow you to make any type in Swift into a nil-able type (though this nil is not exactly the same as an Objective-C nil).
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