$re = '@<[^"]*class="[^"]*(?<="|\s)marginRight(?="|\s[^"]*)"[^"]*href="(?<url>([^?][^\d+]*(?<number>\d+))[^"]*)"@';
$str = '<span class="nav-next-btn nohistory FloatRight">
<span class="nav-next-btn nohistory marginRight">
<a href="http://www.mudah.my/Pahang/nike-for-sale?o=2&q=nike&so=1&th=1" title="Go to next page">
Next ›
</a>
</span>
<a href="http://www.mudah.my/Pahang/nike-for-sale?o=5&q=nike&so=1&th=1" title="Go to last page">
Last »
</a>
</span>';
preg_match_all($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