There are too many coding styles out there, such as PSR-0, PSR-1, PSR-2, PSR-3, and so on. Programmers can use different standards as they want, but it is necessary to follow a standard that is already used in the libraries or a framework in use to make the code more readable. For example, Laravel uses the PSR-1 and PSR-4 coding standards, so if we are developing in Laravel, we should follow these coding standards. Some PHP frameworks, such as Yii 2 and Zend Framework 2, follow the PSR-2 coding standards. However, none of these frameworks stick to a single standard; most of them follow a mixed standard according to their requirements.

The important point is to follow the standard that is used in the libraries used in the application. An organization can also use its own coding standards for internal purposes. It is not a requirement for coding; it is a requirement for readability and producing quality code that others can understand.

PHP Framework Interop Group (PHP-FIG) is...