php - 使用 foreach 连接字符串

Question

我正在尝试生成随机字符。我使用 foreach 循环连接 $char_type 的值，但它没有显示任何内容。这是我的代码:

    public function randomizer($range, $type) {
     $strtester = '';
     $char_type = array('alp_sm' => 'abcdefghijklmnopqrstuvwxyz',
                        'alp_cs' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
                        'num'    => '0123456789',
                        'sp'     => '!@#$%^&*()');

     if(is_array($type)) {
         foreach($type as $row) {
             if(in_array($row, $char_type)) {
                 $strtester .= $char_type[$row];
             }
         }
     }
     print_r($strtester); exit();
     $seed = str_split($strtester);
     shuffle($seed);
     $generated_string = '';
     foreach (array_rand($seed, $range) as $k) $generated_string .= $seed[$k];

     return $generated_string;
    }

更新:我想从 $strtester 得到的是例如我想要 $char_type alp_sm 和 alp_cs 然后 $strtester 将得到 abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

提前谢谢

Answer 1

将 if(in_array($row, $char_type)) { 替换为 if(array_key_exists($row, $char_type)) { 然后尝试

    function randomizer($range, $type) {
         $strtester = '';
         $char_type = array('alp_sm' => 'abcdefghijklmnopqrstuvwxyz',
                            'alp_cs' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
                            'num'    => '0123456789',
                            'sp'     => '!@#$%^&*()');

        if(is_array($type)) {
            foreach($type as $row) {
                if(array_key_exists($row, $char_type)) {
                    $strtester .= $char_type[$row];
                }
            }
        }

        $seed = str_split($strtester);
        shuffle($seed);
        $generated_string = '';
        foreach (array_rand($seed, $range) as $k) 
            $generated_string .= $seed[$k];
        return $generated_string;
    }

    $res =  randomizer(5, array("alp_sm"));
    print_r($res);