How get value for unchecked checkbox in checkbox elements when form posted?

Question

I have a form like below :

<form action="" method="post">
    <input type="checkbox" id="status_1" name="status_1" value="1" />
    <input type="checkbox" id="status_2" name="status_2" value="1" />
    <input type="checkbox" id="status_3" name="status_3" value="1" />
</form>

When i check all checkbox and post the form, the result is like this:

Array ([status_3] => 1 [status_2] => 1 [status_1] => 1 ) 

Then i uncheck second checkbox and post the form, the result is like this:

Array ( [status_3] => 1 [status_1] => 1 ) 

Is it possible to make result like this below when i uncheck second checkbox :

Array ( [status_3] => 1 [status_2] => 0 [status_1] => 1 ) 

There are ideas to do it?

Answer 1

First way - hidden fields (disadvantage: the user can manipulate the value of the field (but one can manipulate the value of the checkbox too, so it's not really a problem, if you only expect 1 or 0))

<form action="" method="post">
<input type="hidden" name="status_1" value="0" />
<input type="checkbox" id="status_1" name="status_1" value="1" />
<input type="hidden" name="status_2" value="0" />
<input type="checkbox" id="status_2" name="status_2" value="1" />
<input type="hidden" name="status_3" value="0" />
<input type="checkbox" id="status_3" name="status_3" value="1" />
<input type="submit" />
</form>
<?php
var_dump($_POST);
/*
 * checking only the second box outputs:
 * 
 * array (size=3)
  'status_1' => string '0' (length=1)
  'status_2' => string '1' (length=1)
  'status_3' => string '0' (length=1)
 */

Second way - to assign default value for non-set indexes:

<form action="" method="post">
<input type="checkbox" id="status_1" name="status_1" value="1" />
<input type="checkbox" id="status_2" name="status_2" value="1" />
<input type="checkbox" id="status_3" name="status_3" value="1" />
<input type="submit" />
</form>
<?php
for($i = 1; $i<=count($_POST); $i++) {
    $_POST["status_$i"] = isset($_POST["status_$i"]) ? $_POST["status_$i"] : 0;
}
var_dump($_POST);

/**
 * Here we will be checking only the third checkbox:
 * 
 * array (size=3)
  'status_3' => string '1' (length=1)
  'status_1' => int 0
  'status_2' => int 0
 */

Answer 2

I think adding hidden fields like this will work

<input type="hidden" id="status_1_" name="status_1"  value="0">
<input type="checkbox" id="status_1" name="status_1" value="1" />

<input type="hidden" id="status_2_" name="status_2" value="0">
<input type="checkbox" id="status_2" name="status_2" value="1" />

<input type="hidden" id="status_3_" name="status_3" value="0">
<input type="checkbox" id="status_3" name="status_3" value="1" />

Answer 3

I thinks it impossible to get array like what you want from html forms. But this some tricks can be used:

$defaultForm = array(
'status_1' => 0,
'status_2' => 0,
'status_3' => 0, 
);

// example array from $_POST
$form = array(
'status_1' => 1,
'status_3' => 1, 
);

$form = array_merge($defaultForm, $form);

Result:

array(3) {

'status_1' => int(1)
'status_2' => int(0)
'status_3' => int(1)

}

Answer 4

Try this. If the checkbox is not checked, then the hidden field with the same name will be passed instead.

<form action="" method="post">
  <input type="hidden" id="hidden_status_1" name="status_1" value="0" />
  <input type="checkbox" id="status_1" name="status_1" value="1" />
  <input type="hidden" id="hidden_status_2" name="status_2" value="0" />
  <input type="checkbox" id="status_2" name="status_2" value="1" />
  <input type="hidden" id="hidden_status_3" name="status_3" value="0" />
  <input type="checkbox" id="status_3" name="status_3" value="1" />
</form>

Answer 5

Thanks all. Thank to @RoyalBg give me solution. Like this :

<input type="hidden" name="status_1" value="0" />
<input type="checkbox" id="status_1" name="status_1" value="1" /> Check 1 <br />
<input type="hidden" name="status_2" value="0" /> 
<input type="checkbox" id="status_2" name="status_2" value="1" /> Check 2 <br />
<input type="hidden" name="status_3" value="0" />
<input type="checkbox" id="status_3" name="status_3" value="1" /> Check 3 <br />

It's work perfectly.. :)

Answer 6

the question may already be answered but i just wanted to take a stab at it...server side only solution:

$p = $_POST;
$a = array();
$a['status_3'] = (int) ($p['status_3'] === 1);
$a['status_2'] = (int) ($p['status_2'] === 1);
$a['status_1'] = (int) ($p['status_1'] === 1);

Testing

 // if input is Array("status_1"=>1) output will be
 Array ( [status_1] => 1 [status_3] => 0 [status_2] => 0 )

 // if input is Array("status_1"=>1, "status_2"=>1) output will be
 Array ( [status_1] => 1 [status_3] => 0 [status_2] => 1)

Answer 7

<!--html code-->                                                                  
<input type="checkbox" name="correct" value="1">Option 1
<input type="checkbox" name="correct" value="2">Option 2
<input type="checkbox" name="correct" value="3">Option 3
<input type="checkbox" name="correct" value="4">Option 4                                   

//php code in function called on form submit       
  public function addOptions(Request $request)
   {
    $option = array('1' => 0,'2'=>0,'3'=>0,'4'=>0 );
    $option[$request->correct] = 1;
    return $option;
   }

Answer 8

Why have you taken it in an array? You can get the unchecked box as 0 by using "isset"

    if(!isset($_POST['status_2'])
    {
      //Set status_2 parameter as 0
    }

Answer 9

try below code

    $myresult = array();

    if(!isset($_POST['status_1'])){ 
        $myresult['status_1'] = 0;
    }
    if(!isset($_POST['status_2'])){ 
        $myresult['status_2'] = 0;
    }
    if(!isset($_POST['status_3'])){ 
        $myresult['status_3'] = 0;
    }

    echo "<pre>";
    print_r($myresult);
    echo "</pre>";
    exit;

Answer 10

Try this one:

for ($i = 1; $i<=3; $i++) {
    $_POST["status_$i"] = isset($_POST["status_$i"]) ? $_POST["status_$i"] : 0; // 0 if not set
}

var_dump($_POST);

Answer 11

Assuming we are using checkboxes with zeros or ones...

Using a hidden checkbox with a zero value is just a work-around. Another work around would be to add 0 to the value when receiving the post or get.

Example:

$chkbx1 = $_POST['chckbx1']; $chkbx1 += 0;

This takes a NULL value an turns it into a zero, but if the value is one, as in its checked, then the value stays the same.

The real issue here isn't inventing a work-around. Its understanding why this is happening. Older versions of mySQL takes null values and converts them into a zero. In newer versions, you must disable strict mode and then a work-around is not needed.