preg_match can be used to parse string using regular expression. The parts of expression enclosed in parenthesis are called subpatterns and with them you can pick individual parts of the string.
$str = "<a href=\"http://example.org\">My Link</a>";
$pattern = "/<a href=\"(.*)\">(.*)<\/a>/";
$result = preg_match($pattern, $str, $matches);
if($result === 1) {
// The string matches the expression
print_r($matches);
} else if($result === 0) {
// No match
} else {
// Error occured
}
Output
Array
(
[0] => <a href="http://example.org">My Link</a>
[1] => http://example.org
[2] => My Link
)