PHP: Retrieving value of checkboxes when name doesn't have array

A form I don't have any control over is POSTing data to my PHP script. The form contains checkboxes along these lines:

<input type="checkbox" value="val1" name="option"/>
<input type="checkbox" value="val2" name="option"/>

If I were to write the code for the form, I'd write name="option[]" instead of name="option". But this is not a change I can do. Now, if both checkboxes are checked, $_POST["option"] returns just one of the values. How can I, in PHP retrieve all the values selected?

From stackoverflow Alessandro Vernet

• You can read the raw post data. For example:

  <fieldset>
      <legend>Data</legend>
      <?php
      $data = file_get_contents("php://input");
      echo $data."<br />";
      ?>
  </fieldset>
  
  <fieldset>
      <legend>Form</legend>
      <form method="post" action="formtest.php">
          <input type="checkbox" value="val1" name="option"/><br />
          <input type="checkbox" value="val2" name="option"/><br />
          <input type="submit" />
      </form>
  </fieldset>
  

  Check both boxes and the output will be:

  option=val1&option=val2
  

  Here's a live demo. All you have to do then is to parse the string yourself, into a suitable format. Here's an example of a function that does something like that:

  function parse($data)
  {
      $pairs = explode("&", $data);
      $keys = array();
      foreach ($pairs as $pair) {
          list($k,$v) = explode("=", $pair);
          if (array_key_exists($k, $keys)) {
              $keys[$k]++;
          } else {
              $keys[$k] = 1;
          }
      }
  
      $output = array();
      foreach ($pairs as $pair) {
          list($k,$v) = explode("=", $pair);
          if ($keys[$k] > 1) {
              if (!array_key_exists($k, $output)) {
                  $output[$k] = array($v);
              } else {
                  $output[$k][] = $v;
              }
          } else {
              $output[$k] = $v;
          }
      }
  
      return $output;
  }
  
  $data = "foo=bar&option=val1&option=val2";
  
  print_r(parse($data));
  

  Outputs:

  Array
  (
      [foo] => bar
      [option] => Array
          (
              [0] => val1
              [1] => val2
          )
  
  )
  

  There might be a few cases where this function doesn't work as expected though, so be careful.

  Ian Elliott : Nice, didn't know that

  Jani Hartikainen : Depending on your PHP settings you may not be able to use file_get_contents on the php://input stream. In this case, you will need to use fopen('php://input', 'r') and stream_get_contents($fp)

  chendral : What PHP settings would that be?
  From Emil H

• Thaks for the great explanation :) You people are sooo good..

  From $pageUsers[$post.author].name