Duplicate values not allowed for select options

What happens if you do it? Do you get an error?
Could you provide a sample module?

Well, I think it is simply a limitation of the API, not an actual bug. There are multiple ways around it:

- Change your select to array(1 => t('January / February / March')
- Do an internal mapping in your submit function like this.

$mapping = array(
 1 => 1,
 2 => 1,
 3 => 1,
 4 => 2,
 // ...
);

$quarter = $mapping[$form_state['values']['quarter']];

You could also provide a patch to allow a array structure like this: array(array('value' => 1, 'title' => t('January')) but this could only be added to D8 (and chances are that it won't be at all).

Changing this to a feature request...

Ran into the same issue while creating options for "sticky" countries above an alpha list of all countries. Same limitation of the Form API.

Looks like the only two options for quite some time are: 1) submit mapping handler - 2) theme layer solution.

Currently Drupal relies on the key to know which value to store and display, so it is only logical that it doesn't allow duplicate keys. So if you really have to provide similar keys, then do a mapping, a parsing or a theme solution. Closing the issue.

Actually, there is a weird branch in form_select_options() that allows you to bypass this and have multiple options with the same key. It involves passing an array of object with an 'option' property.

for example:

$opt1 = new stdClass;
$opt1->option = array(1 => 'Value 1A');
$opt2 = new stdClass;
$opt2->option = array(1 => 'Value 1B');
$options = array($opt1, $opt2);

Then try setting the select form element's options to $options.

See:

https://api.drupal.org/api/drupal/includes%21form.inc/function/form_sele...

#5 works well!!! Thanks.

Thank you for #5.

You can use typecasting and combine with non-object options too:

$options = array(
  (object) array('option' => array('all' => 'Please choose an option')),
  '1' => 'First option',
  '2' => 'Second option',
  (object) array('option' => array('all' => 'Everything')),
);