PHP随机生成一个8位的纯数字编号

//随机生成8位数字
        function nonceStr() {
            static $seed = array(0,1,2,3,4,5,6,7,8,9);
            $str = '';
            for($i=0;$i<8;$i++) {
                $rand = rand(0,count($seed)-1);
                $temp = $seed[$rand];
                $str .= $temp;
                unset($seed[$rand]);
                $seed = array_values($seed);
            }
            return $str;
        }