Solution 1 :

How i said in the comment you can use array_diff for select only the value isn’t selected :

$dbarray = array('1','2','3','4');
$selectedarray = array('1','3');
$substract = array_diff($dbarray, $selectedarray);
print_r($substract); //print 2,4

Problem :

I have a form with other fields, I have a list of clients in a checkbox array. To get that list I use the database table-field and populate a list.

<? if($this->clientCount > 0){?>
  <? foreach($this->client as $valuec) {?>
   <input type="checkbox" name="banner_allowed1[]" value="<?=$valuec['company_id']?>" <?if($valuec['banner_allowed']==1){echo 'checked="checked"';}?> style="margin:auto; size:20px;">&nbsp;<?=$valuec['title']?></label><br>

Now when I submit the form, I need to know which one are unselected, because the form loads with the value selected from the database. I need to update the database table field value to zero(0) for the unselected ones.
I am finding a hard time with dynamic checkboxes to do a name value pair or get values of unselected checkboxes as post doesn’t send unselected checkbox values

MY submit page in POST, only getting checked checkbox values
                foreach($_POST['banner_allowed1'] as $clientid1){     
                  $update['userid'] = $uid;
                  $update['banner_allowed'] = 1;
                  $this->db->update('clientlist', $update, "id=$clientid1");
              } else {



Comment posted by Simone Rossaini

Simple in php page compare mysql and which have selected, then subtract and now you have new array with unselected value

Comment posted by Newbie Coder and Learner

Please show me how to subtract with the original array and posted array. new to this

Comment posted by Newbie Coder and Learner

Thanks so much. Simone. That was so simple. didn’t thought about it.