What are the potential differences in PHP syntax between Windows and Linux systems?

The potential differences in PHP syntax between Windows and Linux systems primarily arise from the use of file paths. Windows systems use backslashes (\) in file paths, while Linux systems use forward slashes (/). To ensure cross-platform compatibility, it's recommended to use the PHP built-in constant DIRECTORY_SEPARATOR when dealing with file paths.

// Use DIRECTORY_SEPARATOR constant to handle file paths in a cross-platform manner
$file_path = 'path' . DIRECTORY_SEPARATOR . 'to' . DIRECTORY_SEPARATOR . 'file.php';