php 将Unicode 转成汉字

<?php 
$s = "\u4e2d\u56fd";//中国
$s=str_replace("\\","%",$s);
function unescape($str) {
	$str = rawurldecode($str);
	preg_match_all("/(?:%u.{4})|.{4};|&#\d+;|.+/U",$str,$r);
	$ar = $r[0];
	foreach($ar as $k=>$v) {
		if(substr($v,0,2) == "%u")
			$ar[$k] = iconv("UCS-2","utf-8",pack("H4",substr($v,-4)));
		elseif(substr($v,0,3) == "")
			$ar[$k] = iconv("UCS-2","utf-8",pack("H4",substr($v,3,-1)));
		elseif(substr($v,0,2) == "&#") {
				$ar[$k] = iconv("UCS-2","utf-8",pack("n",substr($v,2,-1)));
			}
		}
		return join("",$ar);
	}
	echo unescape($s);
?>