In this post, I’ll be sharing clean coding conventions recommended by Robert C. Martin in his video series on “Clean Code”.
Clean code reads like well-written prose.
Grady Booch
Names
- If a comment is required to explain what a variable does, it has a bad name.
- If you have to examine the code that a function executes to understand what it does, it has a bad name.
- All names should be pronounceable.
- Avoid naming things with prefixes and mysterious encodings.
- Variable name lengths should be directly proportional to the size of their scope.
- Class name lengths should be inversely proportional to the size of their scope.
Any fool can write code that a computer can understand. Good programmers write code that humans can understand.
Martin Fowler
Functions
- The first rule of functions is that they’re small. The second rule is that they’re smaller than that.
- Small functions act as sign posts helping people navigate your code.
- Classes and structs hide in long functions.
- Functions should do one thing. If you can extract one function out of another, you know it’s doing more than one thing.
- Extract until you drop!
Redundant comments are just places to collect lies and misinformation.
Robert C. Martin
Function Structure
- Function signatures should be short. A good rule is to have no more than 3 arguments.
- Booleans and potentially null arguments should not be passed into a function. There should be separate functions that handle each case.
- Public functions should be at the top of a chain of private functions where each function only calls functions that are below them.
- Switch statements are a missed opportunity to use polymorphism and also interfere with the principle of independent deployability.
- Functions that return a value should not change state. Functions that change state should not return a value.
- It’s better to throw an exception than to return an error value.
I’m not a great programmer; I’m just a good programmer with great habits.
Kent Beck
Form
- Comments should be rare. Every comment is a failure to properly express yourself in code.
- Keep file sizes small.
- Manage line lengths so you never have to scroll to the right.
- Methods of a class should hide data, not expose it. If they must expose data, they should do it in the most abstract form possible.
- Know the difference between classes and data structures. Classes have private variables and public methods. Data structures have public variables and no methods.
Every time I see commented out code I delete it on the spot. I don’t read it, I don’t try to understand why it’s there, I simply expunge it from existence, and you should do the same.
Robert C. Martin
