PHP人民币金额数字转中文大写的函数代码

<? 
function y($ns) {
    static $ums=array("零","壹","贰","叁","肆","伍","陆","柒","捌","玖"),
        $yunits=array("圆","角","分"),
        $grees=array("拾","佰","仟","万","拾","佰","仟","亿");
    list($ns1,$ns2)=explode(".",$ns,2);
    $ns2=array_filter(array($ns2[1],$ns2[0]));
    $ret=array_merge($ns2,array(implode("",_y_map_unit(str_split($ns1),$grees)),""));
    $ret=implode("",array_reverse(_y_map_unit($ret,$yunits)));
    return str_replace(array_keys($ums),$ums,$ret);
}

function _y_map_unit($list,$units) {
    $ul=count($units);
    $xs=array();
    foreach (array_reverse($list) as $x) {
        $l=count($xs);
        if ($x!="0" || !($l%4)) $n=($x=='0'?'':$x).($units[($l-1)%$ul]);
        else $n=is_numeric($xs[0][0])?$x:'';
        array_unshift($xs,$n);
    }
    return $xs;
}
?>

<?php
 echo y('12121');
?>