Adding option values as an array using a multi selectable select box

Question

I have a plugin I'm developing. As part of its functionality I need to set up an option group and specify an option var for that group:

function swcs_settings() {
  register_setting( 'swcs-settings-group', 'swcs_postpage_id' );
}
add_action( 'admin_init', 'swcs_settings' );

Where swcs_postpage_idis the name of my variable.

I am using this variable in a <select> box like so:

<select name="swcs_postpage_id" id="swcs_postpage_id" multiple>
<?php global $post; 
$args = array( 'numberposts' => -1); 
$posts = get_pages($args); 
foreach( $posts as $post ) : setup_postdata($post); ?>                
    <option value="<? echo $post->ID; ?>"><?php the_title(); ?></option>
<?php endforeach; ?>
</select>

As you can see I am using the <select> with the multiple attribute so a user can make more than one selection if they so desire.

What I'm struggling with is passing more than one value to swcs_postpage_id. I am guessing that the var really needs to be an array and not a var at all but I am not sure what to do in order to:

1. Store multiple values in the option swcs_postpage_id
2. Output and iterate through them using get_option('swcs_postpage_id');

Any help gratefully received.

Answer 1

It's a lot simpler than that:

<select name="swcs_postpage_id[]" id="swcs_postpage_id" multiple>

See those brackets? Boom.