Change property of an object in a foreach loop php

I have an array of objects $comments.
I get it through calling TableGateway wise call to database.

$comments = $this->getCommentsTable()->getComments($theme_id);

I now need to change one of the properties of array object elements:

    foreach ($comments as $comment) {
        $comment->liked = 1;
    }

But the value of $comment->liked doesn't change.

I now need to add a new property disliked:

    foreach ($comments as $comment) {
        $comment->disliked = 1;
    }

But it doesn't add (I know it by the following error):

( ! ) Notice: Undefined property: My\Model\Comments::$disliked  in C:\my\project\module\my\view\Name\operation\comment-info-panel.phtml on line 31
Call Stack
#   Time    Memory  Function    Location
1   0.0008  255368  {main}( )   ..\index.php:0
2   0.1599  6312880 Zend\Mvc\Application->run( )    ..\index.php:26
3   1.8049  9176328 Zend\Mvc\Application->completeRequest( )    ..\Application.php:322
4   1.8049  9176520 Zend\EventManager\EventManager->trigger( )  ..\Application.php:347
5   1.8050  9176648 Zend\EventManager\EventManager->triggerListeners( )

I tried the following with reference:

    foreach ($comments as &$comment) {
        $comment->disliked = 1;
    }

But I get a nasty error:

( ! ) Fatal error: An iterator cannot be used with foreach by reference in C:\My\Project\module\Name\src\Name\Controller\MyController.php on line 804
Call Stack
#   Time    Memory  Function    Location
1   0.0010  255368  {main}( )   ..\index.php:0
2   0.1601  6312880 Zend\Mvc\Application->run( )    ..\index.php:26

Thanks to find a way to modify and/or add a property on an object in this array.

I did it in the following way:

    $commArray = array(); // Create a new array
    $count = $comments->count(); // Get the count of the resultset rows

    // Loop over the count
    for ($i = 0; $i < $count; $i++) {

        // Get the current object
        $curComm = $comments->current();

        // Here I can change easily a property of row object
        $curComm->liked = 1;

        // Here I can easily add a new property to row object
        $curComm->disliked = 1;

        // Set the cursor of the resultset to the next row object
        $comments->next();

        // Add the current row object to the array
        array_push($commArray, $curComm);
    }

    // Do whatever you like with your new array of resultset
    return $commArray;