<?php 

/*

 * 类似QQ聊天时候，有某些关键字可以为他添加上超链接

*/

$string = "aabbcc";

$patterns = array("/a/","/b/","/c/");

$replacements = array_pad(array(),count($patterns),"<a href='#'>$0</a>");

print preg_replace($patterns, $replacements, $string, 1);

?>