PHP 数字金额转换成中文大写金额的函数 数字转中文

/**
*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 == '零元' || $m == '零万' || $m == '零亿' || $m == '零零') {
            $left = substr($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) == '零') {
        $c = substr($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(0.45);