What are some common pitfalls to avoid when using preg_split() to split strings in PHP?

One common pitfall to avoid when using preg_split() in PHP is not properly escaping special characters in the delimiter pattern. This can lead to unexpected behavior or errors when splitting the string. To solve this issue, it is important to use the preg_quote() function to escape any special characters in the delimiter pattern before passing it to preg_split().

// Incorrect way - not escaping special characters in the delimiter pattern
$string = "Hello, World!";
$delimiter = ",";
$parts = preg_split("/$delimiter/", $string);

// Correct way - escaping special characters in the delimiter pattern
$string = "Hello, World!";
$delimiter = ",";
$delimiter = preg_quote($delimiter, '/');
$parts = preg_split("/$delimiter/", $string);