$re = '/\.net\b/';
$str = '"Visited xtreme.com, stupid.net, childish.com, happy.net and innocence.edu. There are some cross.network isssues that are to be fixed."';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
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