正则表达式找到输入值

The string is:

<input type="hidden" name="billing[address_id]" value="34543" id="billing:address_id" />

How can I get input value from this string? I tried this code:

preg_match('/<input type="hidden" name="billing[address_id]" value="(.*?)" id="billing:address_id" \/>/mis', $html, $results);

Your regex is almost correct.. just escape the [ and ] at address_id.

preg_match('/<input type="hidden" name="billing\[address_id\]" value="(.*?)" id="billing:address_id" \/>/mis', $html, $results);