数字转化为人民币大写(PHP)

<?php
function numTrmb($num)
{
    $d = array("零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖");
    $e = array('元', '拾', '佰', '仟', '万', '拾万', '佰万', '仟万', '亿', '拾亿', '佰亿', '仟亿');
    $p = array('分', '角');
    $zheng = "整";
    $final = array();
    $inwan = 0;//是否有万
    $inyi = 0;//是否有亿
    $len = 0;//小数点后的长度
    $y = 0;
    $num = round($num, 2);//精确到分
    if (strlen($num) > 15) {
        return "金额太大";
        die();
    }
    if ($c = strpos($num, '.')) {//有小数点,$c为小数点前有几位
        $len=strlen($num)-strpos($num,'.')-1;//小数点后有几位数
    }else {//无小数点
        $c = strlen($num);
        $zheng = '整';
    }
    for ($i = 0; $i < $c; $i++) {
        $bit_num = substr($num, $i, 1);
        if ($bit_num != 0 || substr($num, $i + 1, 1) != 0) {
            @$low = $low . $d[$bit_num];
        }
        if ($bit_num || $i == $c - 1) {
            @$low = $low . $e[$c - $i - 1];
        }
    }
    if($len!=1){
    for ($j = $len; $j >= 1; $j--) {
        $point_num = substr($num, strlen($num) - $j, 1);
           @$low = $low . $d[$point_num] . $p[$j - 1];
    }
    }else{
        $point_num = substr($num, strlen($num) - $len, 1);
        $low=$low.$d[$point_num].$p[$len];
    }
    $chinses = str_split($low, 3);//字符串转化为数组
    for ($x = count($chinses) - 1; $x >= 0; $x--) {
        if ($inwan == 0 && $chinses[$x] == $e[4]) {//过滤重复的万
            $final[$y++] = $chinses[$x];
            $inwan = 1;
        }
        if ($inyi == 0 && $chinses[$x] == $e[8]) {//过滤重复的亿
            $final[$y++] = $chinses[$x];
            $inyi = 1;
            $inwan = 0;
        }
        if ($chinses[$x] != $e[4] && $chinses[$x] !== $e[8]) {
            $final[$y++] = $chinses[$x];
        }
    }
    $newstr = (array_reverse($final));
    $nstr = join($newstr);
    if ((substr($num, -2, 1) == '0') && (substr($num, -1) <> 0)) {
        $nstr = substr($nstr, 0, (strlen($nstr) -6)).'零'. substr($nstr, -6, 6);
    }
    $nstr=(strpos($nstr,'零角')) ? substr_replace($nstr,"",strpos($nstr,'零角'),6) : $nstr;
    return $nstr = (substr($nstr,-3,3)=='元') ? $nstr . $zheng : $nstr;
}
echo numTrmb(556455456156.65);