I’m new to PHP and would love to ask about how to get multiple values on checkbox based on the question number. I provide a screenshot of a program that i working to.

Question image

This is the PHP generating HTML :

<?php $i = 1; ?>
<?php foreach ($dua as $d) : ?>
    <tr>
      <td><?php echo $i; ?></td>
      <td><?php echo $d['nama_soal'] ?></td>
      <td><img style="border-radius: 5px; width: 375px; height: auto;" src="<?php echo base_url('assets/dashboard/images/soalcfit/subtest2/' . $d['img_soal'] . '.jpg'); ?>" alt=""></td>
      <td>
        <input type="checkbox" class="checkoption<?php echo $d['id'] ?>" name="jsub2[]" value="A"> A
         
        <input type="checkbox" class="checkoption<?php echo $d['id'] ?>" name="jsub2[]]" value="B"> B
         
        <input type="checkbox" class="checkoption<?php echo $d['id'] ?>" name="jsub2[]" value="C"> C
         
        <input type="checkbox" class="checkoption<?php echo $d['id'] ?>" name="jsub2[]" value="D"> D
         
        <input type="checkbox" class="checkoption<?php echo $d['id'] ?>" name="jsub2[]" value="E"> E
         
      </td>
    </tr>
    <?php $i++; ?>
<?php endforeach; ?>

This is the Controller for submitting the post :

public function c2_proses() {
    if ($this->input->post()) {
        //input per subtest
        $jsub2 = $this->input->post('jsub2');

        //untuk foreach soal
        $soal2 = $this->CfitModel->getDataAllSoalSubDua();
        
        //variabel id user
        $id_user = $_SESSION['user_id'];

        //foreach kombinasi sub-1
        foreach($soal2 as $key => $s2)
        {
            $this->CfitModel->inputValue($id_user, $s2['id'], $jsub2[$key]);
        }

        redirect('ujian/csub2');
    }
}

This is the Model :

public function inputValue($id_user, $id_soal, $jawaban) {
    return $this->db->insert('cfit_hasil', array('id_user' => $id_user, 'id_soal' => $id_soal, 'jawaban' => $jawaban));
}

For example i choose A,B from Question number one, and C, D for Question number two, but the output is like this :

1. A
2. B
3. C
4. D

I need my output on the database like :

1. AB
2. CD, etc.