Clean Code PHP

https://github.com/jupeter/clean-code-php#functions

Variables

• use meaningful names
• use searchable names (not numbers)
• avoid nesting deeple, return early
• avoid mental mapping (no $i)
• don’t add uneeded context ($carMake)
• typehint to avoid nulls (string $thing)
• use !== and ===

## Functions

• don’t use flag arguments - have a differnet function instead
• avoid side effects - have one service which writes to a file - don’t use mutable data types
• • don’t change globals
• don’t use Singletons
• Encapsulate conditions $article->isPublished()
• avoid negative conditionals
• avoid conditionals - use polymorphism instead
• avoid type checking - type hint instead
• remove dead code
• use getters and setters
• use private by default

Classes

• prefer composition over inheritance - have a class instead of extending (Employee has EmployeeTaxData)
• avoid fluent
• prefer final classes - use an interface

  SOLID

  Single Responsibility

• Never more than one reason for a class to change - class should just do one thing.

Open/Closed

• Open for extension - closed for modification

  Liskov Substitution

  Interface Segregation

  Dependency Inversion

DRY

Chapter 3 Functions

General

• Small.
• Smaller than that.
• 3 to 4 lines long!
• blocks within if,else and while should be one line long
• • probably a function call
• Adds documentary value - function has descriptive name
• FUNCTIONS SHOULD DO ONE THING. THEY SHOULD DO IT WELL. THEY SHOULD DO IT ONLY.
• one level of indentation

• you need another function if you can extract another function with a new name.

• switch could be a factory

• Remember Ward’s principle: “You know you are working on clean code when each routine turns out to be pretty much what you expected.”

Arguments

• avoid 3 or more arguments

pg 40