Writing Code by the Rules: Code Style and PHP Conventions for the Team

Teamwork: Code Style and Conventions for PHP

Imagine you walk into someone else's PHP project. You open a file, and there — tabs mixed with spaces, variables named haphazardly, and curly braces placed anywhere but where you're used to seeing them. Sound familiar? Now imagine there are hundreds of such files, each written by a different developer. A nightmare for code review and code maintenance.

In this article, we'll break down why PHP code style and code conventions are not just a senior developer's whim, but the foundation of effective teamwork. You'll learn about PSR standards, naming rules, formatting, and get real-world examples you can apply to your project right away.

Why is Code Style Important for a Team?

When multiple developers work on a project, a unified code style becomes a lifesaver. Here's why:

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• Readability. Code written to a single set of rules is easily read by any team member. No need to guess what the author meant.
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• Code review speed. If the code is formatted consistently, the reviewer focuses on logic, not formatting.
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• Fewer bugs. Unified conventions reduce the likelihood of errors caused by different coding approaches.
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• Easy onboarding. A new developer integrates into the project faster when the code is predictable and structured.
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Essentially, PHP coding standards are the language the whole team speaks. The more uniform it is, the less misunderstanding there is.

Key Standards: PSR and Beyond

In the PHP world, there are several key recommendations that have become de facto standards. The most important are PSR-1 and PSR-12 (formerly PSR-2). They are supported by PHP-FIG (Framework Interoperability Group).

PSR-1: Basic Rules

PSR-1 describes the most general rules: how to name classes, methods, constants, and how to organize files.

Key points:

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• Files must use only <?php or <?= (short echo tag).
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• File encoding must be UTF-8 without BOM.
• Class names in StudlyCaps (PascalCase).
• Method names in camelCase.
• Constants in uppercase with underscores (MAX_VALUE).

Example of correct code per PSR-1:

<?php\n\nnamespace App\\Services;\n\nclass UserService\n{\n    const DEFAULT_ROLE = 'user';\n\n    public function getUserById(int $id): ?User\n    {\n        // logic\n    }\n\n    public function isAdmin(): bool\n    {\n        // logic\n    }\n}

PSR-12: Extended Style Rules

PSR-12 is the evolution of PSR-2. It adds more formatting details.

Key points:

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• Indentation: 4 spaces (not tabs).
• Opening braces on the same line for classes, methods, and control structures (K&R style).
• A space is required after keywords (if, else, while).
• Blank line after namespace declaration and before return in methods (optional).
• Line length no longer than 120 characters (80 recommended).

Example of correct formatting per PSR-12:

<?php\n\nnamespace App\\Controllers;\n\nuse App\\Models\\User;\nuse App\\Services\\AuthService;\n\nclass AuthController\n{\n    private AuthService $authService;\n\n    public function __construct(AuthService $authService)\n    {\n        $this->authService = $authService;\n    }\n\n    public function login(array $credentials): bool\n    {\n        if (empty($credentials['email']) || empty($credentials['password'])) {\n            return false;\n