php数目字转汉字的函数算法

/*********************数字转汉字***********************/
function del0($num) //去掉数字段前面的0
{
    return "".intval($num);

}

function n2c($x) //单个数字变汉字

{
    $arr_n = array("零","一","二","三","四","五","六","七","八","九","十");
    return $arr_n[$x];
}

function num_r($abcd) //读取数值（4位）
{
    $arr= array();
    $str = ""; //读取后的汉字数值
    $flag = 0; //该位是否为零
    $flag_end = 1; //是否以"零"结尾
    $size_r = strlen($abcd);
    for($i=0; $i<$size_r; $i++)
    {
        $arr[$i] = $abcd{$i};
    }
    $arrlen = count($arr);
    for($j=0; $j<$arrlen; $j++)
    {
        $ch = n2c($arr[$arrlen-1-$j]); //从后向前转汉字
  		//echo $ch;
  		//echo "<br>";
        if($ch == "零" && $flag == 0){ //如果是第一个零
            $flag = 1; //该位为零
            $str = $ch.$str; //加入汉字数值字符串
            continue;
        }elseif($ch == "零"){ //如果不是第一个零了
            continue;
        }
        $flag = 0; //该位不是零
        switch($j)  {
            case 0: $str = $ch;    $flag_end = 0; break; //第一位（末尾），没有以"零"结尾
            case 1: $str = $ch."十".$str; break; //第二位
            case 2: $str = $ch."百".$str; break; //第三位
            case 3: $str = $ch."千".$str; break; //第四位
        }
    }
    if($flag_end == 1) //如果以"零"结尾
    {
        mb_internal_encoding("UTF-8");
        $str = mb_substr($str, 0, mb_strlen($str)-1); //把"零"去掉
    }
	if($arrlen == 2 && $arr[0] == 1){
		$str = substr($str,2);
	}
    return $str;
}

function num2ch($num) //整体读取转换
{
    $num_real = del0($num);//去掉前面的"0"
    $numlen = strlen($num_real);
 	//echo "numlen=".$numlen."<br>";
    if($numlen >= 9)//如果满九位，读取"亿"位
    {
        $y=substr($num_real, -9, 1);
  //echo $y;
        $wsbq = substr($num_real, -8, 4);
        $gsbq = substr($num_real, -4);
        $a = num_r(del0($gsbq));
        $b = num_r(del0($wsbq))."万";
        $c = num_r(del0($y))."亿";
    }elseif($numlen <= 8 && $numlen >= 5) //如果大于等于"万"
    {
        $wsbq = substr($num_real, 0, $numlen-4);
        $gsbq = substr($num_real, -4);
        $a = num_r(del0($gsbq));
        $b = num_r(del0($wsbq))."万";
  		$c="";
    }elseif($numlen <= 4) //如果小于等于"千"
    {
        $gsbq = substr( $num_real, -$numlen);
        $a = num_r(del0($gsbq));
  		$b="";
  		$c="";
    }
    $ch_num = $c.$b.$a;
    return $ch_num;
}
/******************数字转汉字结束********************/