Teacher, can you explain this chapter in detail?
$pattern=array(
'/\[b\](.*)\[\/b\]/i',
'/\[i\](.*)\[\/i\]/iU',
'/\[u\](.*?)\[\/u\]/i',
'/\[color=(.*?)\](.*?)\[\/color\]/',
'/\[size=(\d)\](.*?)\[\/size\]/',
'/\[qq\](\d{5,12})\[\/qq\]/',
);
//需要替换的UBB字符
$replace=array(
'<b>\\1</b><br />',
'<i>\\1</i><br />',
'<u>\\1</u><br />',
'<font color="\\1">\\2</font><br />',
'<font size="\\1">\\2</font><br />',
'<a href="http://wpa.qq.com/msgrd?V=1&Uin=\\1&Site=[Discuz!]&Menu=yes"
target="_blank"><img src="http://wpa.qq.com/pa?p=1:\\1:1" border="0"></a>',
);
