How do I add multiple post types to this query?

Question

The code i use calls for all attachments that are uploaded to be in the post. I added the Gallery custom post type but nothing shows.

It shows on my "pretty-little-liars" post type though. What am I doing wrong.

   <?php

if ( 'pretty-little-liars','gallery' == get_post_type() ) { //condition to show     gallery on post type - gallery

if ( $attachments = get_children( array(
    'post_type' => 'attachment',
    'post_mime_type'=>'image',   //return all image attachment only
    'numberposts' => -1,   //get all the attachments
    'post_parent' => $post->ID
)));

foreach ($attachments as $attachment) {
    // you can customize the oputput
    echo '<li><p class="alignleft">';
    echo ''.wp_get_attachment_link( $attachment->ID,'full' , false, false );
    echo '</p>';
    echo ''.$attachment->post_excerpt.'<br><br>';
    echo '<p class="alignright"><h5>'.$attachment->post_title. '</h5>';
    echo ''.$attachment->post_content.'';
    echo '</p></li>';
}
}

?>

Answer 1

<?php
if ( 'pretty-little-liars' == get_post_type() || 'gallery' == get_post_type() ) {
    // ...
}
?>