php - 升级到 5.6.x 后如何修复 php 中的引用传递

Question

我最近将 php 5.2 升级到 5.6，但有些代码我还不能修复:

//Finds users with the same ip- or email-address
function find_related_users($user_id) {
    global $pdo;

    //print_R($pdo);

    //Let SQL do the magic!
    $sth = $pdo->prepare('CALL find_related_users(?)');
    $sth->execute(array($user_id));
    //print_R($sth);
    //Contains references to all users by id, to check if a user has already been processed
    $users_by_id = array(); 

    //Contains arrays of references to users by depth
    $users_by_depth = array();

    while ($row = $sth->fetchObject()) {
        //Create array for current depth, if not present
        if (!isset($users_by_depth[$row->depth])) 
            $users_by_depth[$row->depth] = array();

        //If the user is new
        if (!isset($users_by_id[$row->id])) {
            //Create user array
            $user = array(
                'id' => $row->id,
                'name' => $row->name,
                'email' => $row->email,
                'depth' => $row->depth,
                'adverts' => array()
            );

            //Add all users to depth array
            @array_push($users_by_depth[$row->depth], &$user);

            //Add references to all users to id array (necessary to check if the id has already been processed)
            $users_by_id[$row->id] = &$user;
        }
        //If user already exists
        else 
            $user = &$users_by_id[$row->id];

        //Add advert to user
        if ($row->advert_id != null)
            array_push($user['adverts'], array(
                'id' => $row->advert_id,
                'title' => $row->advert_title,
                'msgs' => $row->msgs,
                'url' => $row->url
            ));
        #print_r($user);
        //Unset $user variable !!! 
        //If this is missing, all references in the array point to the same user
        unset($user);
    }

    //Return users, grouped by depth
    return $users_by_depth;
}

如果我简单地删除美元符号前的 & 符号，该函数将停止按预期工作。从关于 stackoverflow 的其他问题中，我发现这是一个引用调用，并且会因新的 php 版本而中断。但是我还没有找到解决方案。

感谢您提供有关如何为 php 5.6.x 更新此代码的任何帮助

Answer 1

您的代码可能从未像您想象的那样工作，因为您正在抑制 array_push() 调用中的错误。请注意，只有 array_push() 的第一个参数通过引用传递，其他值始终通过值传递。

你应该删除错误抑制器 @(永远不要在你自己的代码中使用它)，在这种情况下你也可以这样做:

$users_by_depth[$row->depth][] = &$user;
                            ^^ add an element just like `array_push`

现在您在 $users_by_depth 中的新值将包含对 $user 变量的引用。