php金额如何转大写

/**
*数字金额转换成中文大写金额的函数
*String Int  $num  要转换的小写数字或小写字符串
*return 大写字母
*小数位为两位
**/
function num_to_rmb($num){
    $c1 = "零壹贰叁肆伍陆柒捌玖";
    $c2 = "分角元拾佰仟万拾佰仟亿";
    //精确到分后面就不要了，所以只留两个小数位
    $num = round($num, 2); 
    //将数字转化为整数
    $num = $num * 100;
    if (strlen($num) > 10) {
            return "金额太大，请检查";
    } 
    $i = 0;
    $c = "";
    while (1) {
            if ($i == 0) {
                    //获取最后一位数字
                    $n = substr($num, strlen($num)-1, 1);
            } else {
                    $n = $num % 10;
            }
            //每次将最后一位数字转化为中文
            $p1 = substr($c1, 3 * $n, 3);
            $p2 = substr($c2, 3 * $i, 3);
            if ($n != '0' || ($n == '0' && ($p2 == '亿' || $p2 == '万' || $p2 == '元'))) {
                    $c = $p1 . $p2 . $c;
            } else {
                    $c = $p1 . $c;
            }
            $i = $i + 1;
            //去掉数字最后一位了
            $num = $num / 10;
            $num = (int)$num;
            //结束循环
            if ($num == 0) {
                    break;
            } 
    }
    $j = 0;
    $slen = strlen($c);
    while ($j < $slen) {
            //utf8一个汉字相当3个字符
            $m = substr($c, $j, 6);
            //处理数字中很多0的情况,每次循环去掉一个汉字“零”
            if ($m == &#39;零元&#39; || $m == &#39;零万&#39; || $m == &#39;零亿&#39; || $m == &#39;零零&#39;) {
                    $left = substr($c, 0, $j);
                    $right = substr($c, $j + 3);
                    $c = $left . $right;
                    $j = $j-3;
                    $slen = $slen-3;
            } 
            $j = $j + 3;
    } 
    //这个是为了去掉类似23.0中最后一个“零”字
    if (substr($c, strlen($c)-3, 3) == &#39;零&#39;) {
            $c = substr($c, 0, strlen($c)-3);
    }
    //将处理的汉字加上“整”
    if (empty($c)) {
            return "零元整";
    }else{
            return $c . "整";
    }
}
echo num_to_rmb(23000000.00); //贰仟叁佰万元整