PHP实现：一种隐藏ID的方式

实际场景中，不想吧ID暴露出去，就这么转换。如有需要可以用md5新增校验位。

public static function int_2_str($i,$min_length = 4){
        $str = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T',
        'U','V','W','X','Y','Z'];
        $l = count($str);
        $b_arr = [];
        while(True){
            $s = intdiv($i, $l); //商
            $y= $i % $l;  # 余数
            $b_arr[] = $y;
            if($s == 0){
                break;
            }
            $i=$s;
        }
    
        $b_arr = array_reverse($b_arr);
        $re_str = "";
        foreach($b_arr as $item){
            $re_str =  $re_str.$str[$item];
        }
        $re_str = strtoupper($re_str);
        if(strlen($re_str) < $min_length){
            $need = $min_length - strlen($re_str);
            for($ii =0;$ii<$need;$ii++){
                $re_str = $re_str.strtolower($str[random_int(0,$l-1)]);
            }
        }
        return $re_str;
    }
    
    public static function str_2_int($str = ''){
        $arr = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T',
        'U','V','W','X','Y','Z'];
        $len = count($arr);
        $l = strlen($str);
        $arr_new = [];
        for($ii = 0;$ii<$l;$ii++){
            if (in_array($str[$ii],$arr)){
                $arr_new[] = $str[$ii];
            }
        }
        $l_new = count($arr_new);
        $re_int = 0;
        $arr_new = array_reverse($arr_new);
        for($i=0;$i<$l_new;$i++){
            $index = array_search($arr_new[$i],$arr);
            $re_int = $re_int + $index * pow($len,$i);
        }
        return $re_int;
    }