Question

所以，我有这个非常奇怪的错误 - 一些高级PHP开发人员也可能被认为有些奇怪。

在第二个foreach语句中，我在该foreach语句中创建了一个数组“$ reply_each”，它应该是“array_push（）” - 编入另一个名为“$ recent_discussion_each ['discussion_replies_array']”的数组中。这在第二个foreach声明中有效。但是，只要第二个foreach语句结束，“$ reply_each”数组就会消失 - 好像它超出了范围。为了确保它不是范围问题，我在函数的开头初始化了$ reply_each，但这没有帮助 - 它必须是其他东西。

请帮帮忙？

更新：我可能应该补充一点，当我在第二个foreach语句中对$ recent_discussion_each ['discussion_replies_array']执行count（）时，我得到正确的值1.但是当我执行相同的count（）时，这次在第二个foreach声明之外，我得到一个不正确的值0.这是问题，如果以前不清楚的话。

public function getRecentDiscussions($num_recent_discussions, $course_id) {
    //
    $this->load->database();
    //
    $recent_discussions_array = array();
    //
    // Construct query to fetch recent discussions along with their replies and some
    // basic user info about the authors
    $query_recent_discussions = $this->db->select('course_discussion.id AS course_discussion_id,
                                                   user.f_name,
                                                   user.l_name,
                                                   course_discussion.text,
                                                   course_discussion.posted_datetime,
                                                   course_discussion.is_reply,
                                                   course_discussion.parent_id
                                                  ')
                                         ->join('user', 'course_discussion.owner = user.id')
                                         ->where('course_discussion.course', $course_id)
                                         ->limit($num_recent_discussions)
                                         ->get('course_discussion');
    //
    foreach($query_recent_discussions->result_array() as $row) {
        //
        // Figure out of this comment is a parent or a reply. If it is a parent (meaning is_reply
        // is equal to 0), then treat it like one
        if($row['is_reply'] == '0') {
            //
            $recent_discussion_each = array();
            //
            $recent_discussion_each['discussion_id'] = $row['course_discussion_id'];
            $recent_discussion_each['discussion_owner_f_name'] = $row['f_name'];
            $recent_discussion_each['discussion_owner_l_name'] = $row['l_name'];
            $recent_discussion_each['discussion_body'] = $row['text'];
            $recent_discussion_each['discussion_posted_datetime'] = $row['posted_datetime'];
            $recent_discussion_each['discussion_replies_array'] = array();
            //
            array_push($recent_discussions_array, $recent_discussion_each);
        }
        //
        // Else, it must be a reply since is_reply is not a 0
        else {
            //
            // Look for the parent comment by going through the entire list of comments
            foreach($recent_discussions_array as $potential_parent) {
                //
                // Check to see if this comment's (now known as a reply's) id matches 
                // the id of the comment currently in the position in the list of comments
                if($row['parent_id'] == $potential_parent['discussion_id']) {
                    //
                    $reply_each = array();
                    //
                    $reply_each['reply_id'] = $row['course_discussion_id'];
                    $reply_each['reply_owner_f_name'] = $row['f_name'];
                    $reply_each['reply_owner_l_name'] = $row['l_name'];
                    $reply_each['reply_text'] = $row['text'];
                    $reply_each['reply_posted_datetime'] = $row['posted_datetime'];
                    $reply_each['reply_is_reply'] = $row['is_reply'];
                    $reply_each['reply_parent_id'] = $row['parent_id'];
                    //
                    array_push($potential_parent['discussion_replies_array'], $reply_each);
                }
            }
        }
    }
    //
    foreach($recent_discussions_array as $recent_discussion) {
        echo ($recent_discussion['discussion_id'].' has the following replies: ');
        foreach($recent_discussion['discussion_replies_array'] as $reply) {
            echo($reply['reply_id']);
        }
    }
    //
    return $recent_discussions_array;
    //
    // end
    //
}

Answer 1

foreach创建一个项目副本，供循环体内使用。这意味着$potential_parent实际上不是来自$recent_discussions_array的原始数组，而是它们的副本。

因此，当您修改它们时，只要foreach($recent_discussions_array as $potential_parent)循环结束，这些副本就会消失。

作为我的意思的简化示例，请注意这里明显缺乏任何“baz”打印：

http://ideone.com/WlDru

然后比较如果您实际按密钥访问原始数组会发生什么：

http://ideone.com/etvr5

正如Ben在评论中指出的那样，你真正想要的是使用&运算符：

http://ideone.com/2TphI

PHP数组在foreach语句 - 范围问题中消失了吗？

1 个答案: