php将金额数字转化为中文大写

function toChineseNumber($money){
    $money = round($money * 100, 0);
    $cnynums = array("零","壹","贰","叁","肆","伍","陆","柒","捌","玖");
    $cnygrees = array("分", "角", "圆", "拾","佰","仟","万","拾","佰","仟","亿");
    $reverMoney = strrev(strval($money));
    $len = strlen($reverMoney);
    $return = '';
    for($i=0; $i<$len; $i++) {
        if($reverMoney[$i] != 0) {
            $return .= $cnygrees[$i] . $cnynums[$reverMoney[$i]];
        } elseif($i == 2 && $len == 3) {
            $return .= $cnygrees[$i] . $cnynums[0];
        } elseif($i == 6) {
            $return .= $cnygrees[$i];
        }
    }
    $return = str_rev_gb($return);
    return $return;
}

需要下面反转中英字符函数

// 反转中英文字符
function str_rev_gb($str) {
    if(!is_string($str)||!mb_check_encoding($str,'UTF-8')){
        return false;
    }
    $len = mb_strlen($str,'UTF-8');
    $arr = [];
    for($i=0; $i<$len; $i++) {
        $arr[] = mb_substr($str, $i, 1, 'UTF-8');
    }
    krsort($arr);
    $res = join($arr, '');
    return $res;
}

 单位到亿