ErrorException foreach() argument must be of type array|object, null given

Question

Im using codeigniter 4, and this is my view. I need to get the result from database so I am using php inside the html. I keep getting error exception foreach, but my first foreach working while not the second one.

<div id="container">
    <?php $array1 = array(); ?>
    <?php $array2 = array(); ?>
    <?php $array3 = array(); ?>
    <?php $array4 = array(); ?>
    <?php $array5 = array(); ?>
    <?php $array6 = array(); ?>
    <?php $array7 = array(); ?>
    <?php $array8 = array(); ?>


    <?php foreach($checks as $checkans){?>
        <?php array_push($array1, $checkans);
    } ?>

   
   <!--STARTS ERROR HERE--> 

    <?php foreach($results as $res){?>
        <?php array_push($array2, $res->answer);
          array_push($array3, $res->quizID); 
          array_push($array4, $res->question);   
          array_push($array5, $res->choice1);
          array_push($array6, $res->choice2);
          array_push($array7, $res->choice3);
          array_push($array8, $res->choice4); 
    } ?>

          <?php
          for ($x=0; $x<10; $x++){ ?>

          <p><?=array3($x)?>.<?=array4($x)?></p>

          <?php if($array2($x)!=$array1($x)) {?>
            <p><span style="background-color: #FF9C9E"><?=$array1($x)?></span></p>
            <p><span style="background-color: #ADFFB4"><?=$array2($x)?></span></p>
        
        <?php } else { ?>

            <p><span style="background-color: #ADFFB4"><?=$array1($x)?></span></p>

        <?php }} ?>

</div>