Validation Strategy in PHP (Centralized and Clean)

Validation is where many apps become messy. A clean approach is: - define expected fields - validate rules - return clear errors ## Simple validation helper idea ```php function require_string(array $data, string $key, int $min = 1): string { $val = trim((string)($data[$key] ?? '')); if (strlen($val) < $min) { throw new Exception("$key is required"); } return $val; } ``` Usage: ```php try { $title = require_string($input, "title", 3); $body = require_string($input, "body", 10); } catch (Exception $e) { json_error("VALIDATION_ERROR", $e->getMessage(), 422); } ``` ## Why 422 Many APIs use 422 Unprocessable Entity for validation errors. > Next: Laravel introduction (because many PHP careers use it).