Learning about PHP Coding Style

I know that common coding style is helpful for cooperation. But unfortunately, I’m working alone so I didn’t understand it’s importance.

When I decide refactoring my legacy source code, I found the QUITE DIRTY CODE. So I make up my mind studying about PHP coding style.

PSR-1: Basic Coding Standard

PSR-1: Basic Coding Standard — PHP-FIG

PHP Basic coding standard are described in RFC 2119.

1. PHP code MUST use only<?php &<?= tags.
2. PHP code MUST use only UTF-8 without BOM.
3. A file SHOULD either declare new symbols (classes, functions, constants, etc.) or cause side effects, but SHOULD NOT do both.
4. Namespaces and classes MUST follow PSR-0: Autoloading Standard & PSR-4: Autoloader.
5. Classes MUST be declared in Pascal Case(PascalCase) or
6. Constants of classes MUST be declared in All Caps Snake Case(ALL_CAPS_SNAKE_CASE).
7. Methods MUST be declared in Camel Case(camelCase).

PSR-12: Extended Coding Style