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.”

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 Xcode Preprocessor Macros
2. #imports Gone Wild! How to Tame File Dependencies
3. 4 Ways Precompiled Headers Cripple Your Code
4. Is Dot Notation in Objective-C 100% Pure Evil?
   …or maybe not! I switched, see In Which I Embrace Dot Notation…
5. Objective-C init: Why It’s Helpful to Avoid Messages to self

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!

Other resources:

• Refactoring: The Book that Changed Everything for Me
• Martin Fowler explains “code smell”
• Summary of code smells from the book, with the refactorings to fix them

Question: What common Objective-C practices have you encountered that you might consider code smells? Leave a comment below.