Code Smells in Objective-C

Code smells. I’ve mentioned “code smells” at work, only to discover that my coworkers didn’t know what I meant. It’s basically a diaper-changing metaphor: “If it stinks, change it.”

“If it stinks, change it.”

A code smell isn’t “awful code that makes you hold your nose.” Rather, it’s a simple indication that something may need to be changed. Quite often, you won’t notice a code smell until someone else describes it. This is what Kent Beck and Martin Fowler did in the Refactoring book: created a list of smells, and what to do about them.

Code Smells Specific to Objective-C

The book’s catalog of code smells relate to good practices of object-oriented programming. I’m going to start a series that is specific to Objective-C code smells. Here’s a tentative list to give you a preview:

1. 9 Code Smells of Preprocessor Use
2. #imports Gone Wild! How to Tame File Dependencies
3. 4 Ways Precompiled Headers Cripple Your Code
4. Dot Notation in Objective-C: 100% Pure Evil
5. Don’t Message self in Objective-C init (and dealloc)

I think this’ll be interesting, and sometimes even controversial. (Dot notation, anyone?) So be sure to come back — subscribe to keep up with the latest postings!

And in the meantime, check out these related resources:

• The Refactoring Book: A Game-Changer
• Martin Fowler explains “code smell”
• Summary of code smells from the book, with the refactorings to fix them

Photo by *bethography* (license), adapted by Jon Reid