php实现数字金额转换成中文大写金额

<?php
header("content-type : text/html ;charset=utf-8");
/**
 *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 ( 2340555.34 );