PHP DocBlocks and PHPDoc Types

PHPDoc comments describe parameters, return values and generics for humans and static analyzers.

The examples focus on the operation itself, including the important distinction: PHP attributes are machine-readable runtime metadata; DocBlocks are structured comments.

What It Does

Use the examples below to observe the behavior on a small dataset before extending it to application code.

Before You Start

Read the input requirements before applying this pattern to production data.

Example 1: Basic Use

Native return type int is enforced at runtime; @param list<int> is an annotation understood by supporting analyzers.

<?php
/**
 * @param list<int> $values
 * @return int
 */
function sumValues(array $values): int { return array_sum($values); }
echo sumValues([1, 2, 3]);

Output from a successful local PHP 8.4 run:

6

Example 2: Checking Behavior

Native return type int is enforced at runtime; @param list<int> is an annotation understood by supporting analyzers.

<?php
/**
 * @param list<int> $values
 * @return int
 */
function sumValues(array $values): int { return array_sum($values); }
echo sumValues([2, 3, 4]);

Output from a successful local PHP 8.4 run:

9

Example 3: Practical Example

Native return type int is enforced at runtime; @param list<int> is an annotation understood by supporting analyzers.

<?php
/**
 * @param list<int> $values
 * @return int
 */
function sumValues(array $values): int { return array_sum($values); }
echo sumValues([3, 4, 5]);

Output from a successful local PHP 8.4 run:

12

Important Behavior and Edge Cases

PHPDoc annotations do not enforce runtime types; native PHP types remain the execution contract.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• PHPDoc comments describe parameters, return values and generics for humans and static analyzers.
• PHPDoc annotations do not enforce runtime types; native PHP types remain the execution contract.
• PHP attributes are machine-readable runtime metadata; DocBlocks are structured comments.

Use PHP DocBlocks and PHPDoc Types when its documented behavior matches the problem. Test the relevant edge cases in your own runtime before deploying it.