What are some best practices for naming variables and files in PHP to ensure clarity and consistency in code?

When naming variables and files in PHP, it is important to follow best practices to ensure clarity and consistency in your code. Some tips include using descriptive and meaningful names, avoiding abbreviations, using camelCase for variables, and following a consistent naming convention throughout your codebase.

// Example of naming variables in PHP using best practices
$firstName = "John";
$lastName = "Doe";

// Example of naming files in PHP using best practices
include "functions.php";