Page 6 - PHP

Anyone who catches every exception with a blanket catch (\Exception $e) loses the distinction between programming mistakes and expected runtime problems. This article shows how the built-in Throwable hierarchy and the SPL exceptions of PHP 8.4 enable robust error handling, including try/catch/finally, error conversion and clean exception logging.

Constructor property promotion collapses the classic threefold repetition of property declaration, constructor parameter, and body assignment into a single line per field, without giving up type safety, visibility, or readonly guarantees, and makes value objects and DTOs in particular noticeably more compact and maintainable.

Scattered mysql_ calls and string-concatenated SQL queries are one of the most common and most dangerous inheritances of old PHP projects. This article shows how to systematically replace such legacy database access with a unified PDO layer built on prepared statements, without interrupting operations.

Fibers give PHP code the ability to pause execution at almost any point in the call stack and resume exactly there later, without restructuring the calling logic into callbacks or generators. This article walks through the Fiber class step by step, from start and resume through error handling with throw to a custom cooperative scheduler and the real costs in memory and stack usage.

A PHP object without a single property still occupies several dozen bytes in memory, purely from the internal zend_object header. Anyone seeing unexpectedly high memory usage with thousands of objects per request usually finds the cause in the interplay of object header, property table and the size of typed properties, not in the actual payload.

An abstract class and an interface appear at first glance to solve a similar problem, namely defining a contract that concrete classes must follow. The decisive difference lies in what each construct actually brings along: an interface is a pure contract with zero implementation, an abstract class, on the other hand, can contain constructors, shared state, and concrete methods that every subclass inherits automatically. This article uses a running report generator example to show when each tool is the right choice, why PHP's single inheritance restriction shapes this decision decisively, and how both concepts work together cleanly in a single class hierarchy.

A network error after a successful payment leads, without protection, to the client repeating the same request and triggering a second payment. This article shows how idempotency keys are implemented in PHP APIs to reliably prevent exactly this problem, including request fingerprinting, response caching, and protection against race conditions.

Composer can do far more than just install dependencies: through Composer scripts and lifecycle hooks, every step of the installation process, from the very first composer install to the last autoload dump, can be extended with custom automation. Whether a shell command or a PHP callback via Composer\Script\Event, anyone who knows the complete event list replaces manual setup steps, forgotten cache clears, and improvised onboarding instructions with reproducible, versioned automation right inside composer.json.

A persistent data structure keeps its old version fully intact after every change and produces a new version instead, without copying the entire content. In PHP 8.4 this principle can be implemented directly with immutable linked lists and structural sharing, with no external library required.

PHPStan level max uncovers error classes that unit tests often miss: wrong argument types, risky null access, unreachable code. A growing project does not reach this level overnight, but through level ratcheting, a maintained baseline file, cleanly typed generics and custom rules for project-specific conventions.