What are the best practices for handling autoload functions in PHP to ensure proper class loading?

When using autoload functions in PHP, it is important to follow best practices to ensure proper class loading. One common approach is to use the spl_autoload_register() function to register an autoload function that will be called whenever a class is not found. This function should follow PSR-4 naming conventions and use namespaces to map class names to file paths. By organizing your classes and files in a standardized way and registering a reliable autoload function, you can ensure that your classes are loaded correctly when needed.

spl_autoload_register(function($class) {
    // Convert class name to file path
    $file = str_replace('\\', '/', $class) . '.php';
    
    // Check if file exists and require it
    if (file_exists($file)) {
        require_once $file;
    }
});