How can I access values of multiple select list in a form?

Question

I have a custom form in a custom module with multiple select:

$form['sponsors'] = array(
 '#type' => 'select',
 '#options' => $sponsors,
 '#multiple' => TRUE,
 '#size' => 20,
);

But I'm stumped how to access the submitted multiple values in the form_submit function. I tried to get the values by looping through the key (one guess was $form['values']['sponsors'][$key]) but no luck... anyone can point me in right direction would be appreciated!

Answer 1

Submitted data goes into $form_state['values'] (not $form['values']), and in the case of a multiple select/checkbox element you can filter out the selected items like this:

function MYMODULE_form_submit($form, &$form_state) {
  $selected = array_filter($form_state['values']['sponsors']);
}

As monymirza mentioned you're also missing the # symbol at the start of both the size and multiple keys. I imagine that error is just in your question, not in your actual code, or you'd expect to see more errors.

Answer 2

in case whether the user may select more than one item, size value be written like this way:

'#size' => $multiple ? min(12, count($options)) : 0,

this is how used in (taxonomy.module).