PHP Doc

Documentation (phpDoc)

• GOLDEN RULE: Never duplicate signature information without adding value
• For trivial methods where class, method name, and parameter names explain everything
• When documentation would only repeat signature information
• Clearly define purpose/responsibility
• Use active phrasing describing main responsibility
• Avoid unnecessary words
• Be concise and direct

Class Documentation

Writing Style

• Skip phrases like "Class that..." or "Interface for..."
• Don't duplicate method lists or implementation details

Property Documentation

• Use single-line format for simple @var annotations:

/** @var string[] */
private array $name;

Method Documentation

Writing Style

• Start with 3rd person singular present tense verb
• Prefer verbs like Returns, Formats, Checks, Creates, Converts, Sets

Parameters and Return Values

• Only document when adding information beyond PHP types
• Add information about:
  • Array contents (e.g., @return string[])
  • Specific formats or value ranges
  • Important verbal descriptions
• Use two spaces after type: @return string primary column sequence name
• Use two spaces after param: @param mixed $var
• Skip for self-explanatory parameters (width, height, name)
• Include only when explaining:
  • Additional context
  • Limitations or conditions
  • Unusual usage

Exception Documentation

• Avoid phrases like "Exception that is thrown when"
• Use natural language and active voice
• Ideally use a single sentence
• Describe the problem, not technical context
• Use consistent phrases across exceptions:
  • "does not exist" for missing items
  • "failed to" for operation failures
  • "cannot" for impossible operations
  • "is not supported" for unsupported features
• Avoid technical jargon, redundant words, implementation details

Examples:

• "The file does not exist."
• "Cannot access the requested class property."
• "The value is outside the allowed range."
• "Failed to read from or write to a stream."

Examples

Good Documentation

Clear purpose, adding information about array contents:

/**
 * Returns list of supported languages.
 * @return string[]  Array of language codes
 */
public function getSupportedLanguages(): array

Describing unusual behavior:

/**
 * Creates new transaction. Returns null if user has exceeded daily limit.
 */
public function createTransaction(float $amount): ?Transaction

Short for properties:

/** for back compatibility */
protected Explorer $context;

When to Skip Documentation

When signature provides all needed information and purpose obvious:

protected readonly string $name;

public function getWidth(): int

For self-explanatory parameters:

/**
 * Calculates dimensions of image cutout.
 */
public function calculateCutout(int $left, int $top, int $width, int $height): array