What is Primitive Obsession?

Primitive Obsession is a code smell or anti-pattern where developers rely heavily on primitive data types (such as integers, strings, or booleans) instead of encapsulating related data into well-defined domain objects³. Here are some key points:

1. Definition: Primitive fields are basic built-in building blocks of a language. They're usually typed as int, string or constants etc¹.
2. Problem: Primitive Obsession is when the code relies too much on primitives. It means that a primitive value controls the logic in a class and this value is not type safe¹.
3. Example: For instance, consider representing a website’s URL. You normally store it as a String. But a URL has more information and specific properties compared to a String (e.g. the scheme, query parameters, protocol). By storing it as a String you can no longer access these URL-specific items without additional code¹.

This practice can lead to several drawbacks, such as increased complexity and decreased readability, which is why it's considered a bad practice³. It's recommended to use well-defined domain objects instead².

Appendix

Source: Conversation with Bing, 06/02/2024

1. The Pitfalls of Primitive Obsession: An Insight into Code Quality - Medium.
2. Primitive Obsession — A Code Smell that Hurts People the Most.
3. Collections and Primitive Obsession · Enterprise Craftsmanship.
4. Primitive Obsession Code Smell Resolution with example.