The code shown herein will only compile and link in Xcode 10 beta and run on iOS 12 beta and/or OS X 10.14 beta.
We’re in the middle of Apple’s annual product upgrade cycle and this article is the second in a series of tutorials, started last week, meant to highlight the most important new features of Swift 4.2. Today, we’ll look at two two new Swift 4.2 features, the
#error compiler directives.
Continue reading “Swift 4.2 improvements: #warning and #error compiler directives”
In this tutorial, the third in a series of tutorials, we’re going to finish the arduous topic of looking for unexpected values, events, and conditions that arise during program execution, using a technique I like to call “error checking.” Today, I’ll concentrate on
nil values, optionals, optional binding, the
guard statement, failable initializers, and finally, give you some advice about keeping your error checking code consistent, for example, when to use Swift “Error Handling” or when just to return
true/false or use
Continue reading “Controlling chaos: Error checking in Swift 4 with if let, guard, and failable initializers”
[Download the Xcode 9 playground from GitHub so you can follow along with my detailed discussion and try iOS error handling using the
do-try-catch feature yourself!]
This tutorial is the second in my series of tutorials on incorporating error checking into your Swift 4-based iOS apps. Remember that by “error checking,” I mean gracefully handling “unexpected values, events, and conditions that arise during program execution.” Today, I’ll limit my discussion of error checking to what Swift’s authors call “Error Handling.” Please read my first, introductory article in this series if you haven’t already. I can’t emphasize enough why you need to use error checking. Remember my discussion of app quality, user intolerance of buggy apps, and the huge amount of choices consumers have? The quality of your apps represents your reputation. Do you want a bad reputation when customers choose apps largely based on reviews? They can and will vote with their fingers (and wallets) and find other apps if they don’t like your app(s). Download my Xcode 9 playground so you can follow along with my discussion, run the code, and experiment with my Swift code by making your own changes.
Continue reading “Controlling chaos: Error Handling in Swift 4 with do, try, catch, defer, throw, throws, Error, and NSError”
NOTE: The second installment of this article, “Controlling chaos: Error Handling in Swift 4 with do, try, catch, defer, throw, throws, Error, and NSError,”, has just been released.
In this tutorial, the first in a series of tutorials, we’re going to discuss the arduous topic of looking for unexpected values, events, and conditions that arise during program execution, using a technique I like to call “error checking.” Today, I’ll concentrate on the reasons why you should check for errors. I’ll mention a number of techniques I use but leave detailed discussion of those techniques and sample code to subsequent articles. The purpose of this tutorial is to convince you to make use of error checking in your apps. You ignore errors at your own dire peril. This is sink or swim. If you put out a crappy app, no one’s going to use it because you’ll get a bad reputation at Internet speed, and employers/customers will be more than happy to leave you behind forever for other app developers who aren’t too lazy to write quality code.
Continue reading “Controlling chaos: Why you should care about adding error checking to your iOS apps”