Code Smell 27 — Associative Arrays
[Key, values], magic, fast, malleable and error prune.
Problems
- Coupling
- Information Hiding
- Code Duplication
- Fail Fast
- Integrity
Solutions
- Reify objects
- Create cohesive small objects
- Don’t leave them anemic, find their cohesive relations.
Sample Code
Wrong
Anemic
Validated
Right
Degrees deserves reification
Many people suffer from primitive obsession and believe this is over design. Designing software is about making decisions and comparing trade-offs. The performance argument is not valid nowadays since modern virtual machines can efficiently deal with small short-lived objects.
Detection
We cannot forbid Associative Arrays since they are very good as a first approach.
They will be fine for exporting data, serialization, persistence and other accidental implementation issues.
We should avoid them on our systems.
Tags
- Primitive
Conclusion
When creating objects we must not think of them as data. This is a common misconception.
We should stay loyal to our Bijection and discover real world objects.
Most associative arrays have cohesion and represent real world entities, and we must treat them as first class objects.
Relations
There’s nothing more permanent than a temporary hack.
Kyle Simpson
This article is part of the CodeSmell Series.
