Coding Standards

Naming Conventions

Variables

Use descriptive, meaningful variable names in camelCase. Avoid single-letter or ambiguous names.

// Good
$userName = 'John Doe';
$invoiceTotal = 1500;

// Bad
$u = 'John Doe';
$x = 1500;

Methods

Method names should be in camelCase and clearly describe their purpose. Use verbs for actions.

// Good
public function getUserName()
{
    return 'John Doe';
}
public function calculateInvoiceTotal($items)
{
    // ...
}

// Bad
public function getuser() {
    return 'John Doe';
}
public function calc() {
    // ...
}

Classes

Class names should use PascalCase and be singular, representing a single entity or concept.

// Good
class UserManager
{
    // class content
}

class Invoice
{
    // ...
}


// Bad
class user_manager
{
    // class content
}
class invoices
{
    // ...
}

Constants

Constants should be in UPPER_CASE with underscores. Use them for values that do not change.

// Good
const MAX_USER_COUNT = 100;
const DEFAULT_TIMEOUT = 30;

// Bad
const maxUserCount = 100;
const defaultTimeout = 30;

Formatting

Indentation

Use 4 spaces per indentation level. Do not use tabs. Indent consistently for readability.

// Good
if ($condition) {
    echo 'true';
}

// Bad
if ($condition) { echo 'true'; }

Line Length

Keep lines under 80 characters. Break long statements into multiple lines.

// Good
$longString = 'This is a long string that is split across multiple lines to keep each line under 80 characters.';

Blank Lines

Use blank lines to separate logical sections of code, such as between functions or class methods.

// Good
public function firstFunction()
{
    // function body
}

public function secondFunction()
{
    // function body
}

// Bad
public function firstFunction()
{
    // function body
}
public function secondFunction()
{
    // function body
}

Comments

Use comments to explain non-obvious code. Write comments above the code they describe, not inline. Avoid redundant comments.

// Good
// This function returns the user's name
public function getUserName(): string
{
    return 'John Doe';
}

// Explain complex logic
// Calculate the total invoice amount including tax
public function calculateInvoiceTotal($items)
{
    // ...
}

// Bad
public function getUserName(): string
{
    return 'John Doe'; // returns name
}

Additional Best Practices

• Use type hints and return types in functions and methods for clarity and error prevention.
• Group related functions and classes together in files and folders.
• Avoid magic numbers and strings; use named constants instead.
• Use PSR-12 coding style as a baseline for formatting and structure.
• Refactor duplicated code into reusable functions or classes.
• Write self-documenting code: code should be clear enough that comments are only needed for complex logic.

Example: Comprehensive Class

/**
 * Manages user operations such as registration and authentication.
 */
class UserManager
{
    /**
     * Registers a new user.
     *
     * @param array $data
     * @return User
     */
    public function register(array $data): User
    {
        // ... registration logic ...
    }

    /**
     * Authenticates a user.
     *
     * @param string $email
     * @param string $password
     * @return bool
     */
    public function authenticate(string $email, string $password): bool
    {
        // ... authentication logic ...
    }
}