When you’re learning about databases or multithreaded programming, it’s likely that you’ll come across the term "atomic" at some point. Usually you’ll hear the term in the context of an operation. For example, an atomic read / write operation. Or atomic access to a property. But what does this mean? Read more…
Working with dates is hard, there is no doubt about that. And formatting dates properly for every user of your app is no easier (if you want to do everything manually). Luckily, the system can help us. For example, in the US one would write "October 15" while in The Read more…
Apple introduced SF Symbols in iOS 13. SF Symbols allow developers to easily integrate icons in their apps. The SF Symbols icons integrate really well with the default system font, and provide a consistent look throughout the system. In iOS 14, Apple added over 750 new icons to the SF Read more…
A Double and Float are both used to represent decimal numbers, but they do so in slightly different ways. If you initialize a decimal number in Swift using as shown below, the Swift compiler will assume that you meant to create a Double: let val = 3.123 // val is Read more…
There are several ways to handle errors in Combine. Most commonly you will either use catch or replaceError if you want to implement a mechanism that allows you to recover from an error. For example, catch is useful if you want to retry a network operation with a delay. The Read more…
After using a MacBook that runs Xcode for a few years it’s likely that your disk space is starting to fill up good. A large part of this disk space can be occupied by Device Support files that are used by Xcode for older iOS versions, or by iOS simulators Read more…
Sometimes you’ll want to test whether your app works properly under poor networking conditions. One way to test this is Apple’s Network Link Conditioner. Unfortunately, this will slow internet speeds for your entire machine to a crawl which can be counterproductive. Especially if you want to throttle your app for Read more…
Collection views in iOS are awesome. You can use them to build complex custom layouts and since iOS 13 you can use Compositional Layouts to quickly build good looking layouts that would take forever to accomplish on iOS 12 and below. But what if you want to use more than Read more…
One of Combine’s somewhat painful to work with features is its error mechanism. In Combine, publishers have an Output type and a Failure type. The Output represents the values that a publisher can emit, the Failure represents the errors that a publisher can emit. This is really convenient because you Read more…
There are several ways to initialize and configure properties in Swift. In this week’s Quick Tip, I would like to briefly highlight the possibility of using closures to initialize complex properties in your structs and classes. You will learn how you can use this approach of initializing properties, and when Read more…