What are the potential pitfalls of using regular expressions and backslashes in PHP?

When using regular expressions in PHP, backslashes are used as escape characters. This can lead to confusion and errors, especially when dealing with paths or URLs that contain backslashes. To avoid this issue, it is recommended to use single quotes or double quotes with double backslashes to properly escape backslashes in regular expressions.

// Example of using double backslashes to escape backslashes in a regular expression
$pattern = '/C:\\\\Users\\\\example/';