$re = '/[,.!?]/';
$str = 'This is a test for replacing characters:
Dots..., question marks?, exclamation marks!
And of course, the comma.';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php