how to pass values of unchecked boxes only?

Question

I am working on a html form where I have a number of checkboxes, but I want to pass only the unchecked values to another form (get_value.php).

   <form action="get_value.php" method="post">
     <input type='checkbox' name='products[]' value='call1'>col1<br>
     <input type='checkbox' name='products[]' value='call2'>col2<br>
     <input type='checkbox' name='products[]' value='call3'>col3<br>
     <input type='checkbox' name='products[]' value='call4'>col4<br>
     <input type='submit'  value='Submit'>
   </form>

Is there any way to filter $_POST['products'] to get unchecked values only?

Possible duplicate of [How get value for unchecked checkbox in checkbox elements when form posted?](http://stackoverflow.com/questions/19239536/how-get-value-for-unchecked-checkbox-in-checkbox-elements-when-form-posted) — Syed mohamed aladeen, May 24 '16 at 11:10

score 1 · Answer 1 · answered May 24 '16 at 11:14

Unchecked checkboxes are not sent at all. If you, for example, check col1 and col2, the following POST data will be sent to get_value.php:

array(
    'products' => array(
        'call1',
        'call2',
    ),
)

If you want to determine which ones weren't checked, do this:

$values = array(
    'call1',
    'call2',
    'call3',
    'call4',
);

$unchecked = array_diff($values, $_POST['products']);

var_dump($unchecked);

Result:

array(2) {
  [2]=>
  string(5) "call3"
  [3]=>
  string(5) "call4"
}

score 0 · Answer 2 · answered May 24 '16 at 11:35

You can also get unchecked checkbox values in javascipt.

Try this

$('#q').submit(function(e) {
    $('input[type="checkbox"]').each(function(index) {
        if(!this.checked) {
           alert(this.value);
        }
    });
    e.preventDefault();
});

Here q will be formID.

how to pass values of unchecked boxes only?

2 Answers2