For some time, Drupal's PHP coding standards allows for writing variables in either snake-case (e.g. $my_variable) or lower camel-case (e.g. $myVariable).
It originally only allowed for snake-case variable names but once it accepted both, I switched to camel-case as my default.
Why? I didn't like the inconsistency of using one approach for variable names and one for method and property names in PHP classes (which were always camel-case).
I'd have had code like this with a mixture of both:
class MyClass {
private EntityTypeManagerInterface $entityTypeManager;
public function __construct(EntityTypeManagerInterface $entity_type_manager) {
$this->entityTypeManager = $entity_type_manager;
}
}
I prefer not to have to consistently think about which to use and, if possible, like to use standard approaches in different codebases whether I'm working on a Drupal project, a Symfony project, or a PHP library.
I'm an Acquia-certified Drupal Triple Expert with 17 years of experience, an open-source software maintainer and Drupal core contributor, public speaker, live streamer, and host of the Beyond Blocks podcast.