php程序中获取汉字拼音的首字母的方法

//php获取中文字符拼音首字母 
function getFirstCharter($str){ 
 if(empty($str)){return '';} 
 $fchar=ord($str{0}); 
 if($fchar>=ord(&#39;A&#39;)&&$fchar<=ord(&#39;z&#39;)) return strtoupper($str{0}); 
 $s1=iconv(&#39;UTF-8&#39;,&#39;gb2312&#39;,$str); 
 $s2=iconv(&#39;gb2312&#39;,&#39;UTF-8&#39;,$s1); 
 $s=$s2==$str?$s1:$str; 
 $asc=ord($s{0})*256+ord($s{1})-65536; 
 if($asc>=-20319&&$asc<=-20284) return &#39;A&#39;; 
 if($asc>=-20283&&$asc<=-19776) return &#39;B&#39;; 
 if($asc>=-19775&&$asc<=-19219) return &#39;C&#39;; 
 if($asc>=-19218&&$asc<=-18711) return &#39;D&#39;; 
 if($asc>=-18710&&$asc<=-18527) return &#39;E&#39;; 
 if($asc>=-18526&&$asc<=-18240) return &#39;F&#39;; 
 if($asc>=-18239&&$asc<=-17923) return &#39;G&#39;; 
 if($asc>=-17922&&$asc<=-17418) return &#39;H&#39;; 
 if($asc>=-17417&&$asc<=-16475) return &#39;J&#39;; 
 if($asc>=-16474&&$asc<=-16213) return &#39;K&#39;; 
 if($asc>=-16212&&$asc<=-15641) return &#39;L&#39;; 
 if($asc>=-15640&&$asc<=-15166) return &#39;M&#39;; 
 if($asc>=-15165&&$asc<=-14923) return &#39;N&#39;; 
 if($asc>=-14922&&$asc<=-14915) return &#39;O&#39;; 
 if($asc>=-14914&&$asc<=-14631) return &#39;P&#39;; 
 if($asc>=-14630&&$asc<=-14150) return &#39;Q&#39;; 
 if($asc>=-14149&&$asc<=-14091) return &#39;R&#39;; 
 if($asc>=-14090&&$asc<=-13319) return &#39;S&#39;; 
 if($asc>=-13318&&$asc<=-12839) return &#39;T&#39;; 
 if($asc>=-12838&&$asc<=-12557) return &#39;W&#39;; 
 if($asc>=-12556&&$asc<=-11848) return &#39;X&#39;; 
 if($asc>=-11847&&$asc<=-11056) return &#39;Y&#39;; 
 if($asc>=-11055&&$asc<=-10247) return &#39;Z&#39;; 
 return null; 
}