PHP Warning: Invalid argument supplied for foreach

Question

I have this error coming up on my wp_debug log file: [09-Aug-2016 11:05:05 UTC] PHP Warning: Invalid argument supplied for foreach() in ...wp-content/themes/mytheme/custom-post-types/cpts.php on line 23

I cannot seem to see why this would give that that error...

The code in question is as follows

$cpts = array(
    array('shows','Show','Shows','dashicons-tickets-alt',array('title','editor','thumbnail','comments')),
    array('people','Person','Team','dashicons-groups',array('title','editor','thumbnail')),
    array('cast','Cast & Crew','Cast & Crew','dashicons-universal-access',array('title','editor','thumbnail')),
    array('brochures','Brochure','Brochures','dashicons-book',array('title','editor','thumbnail')),
    array('jobs','Job','Jobs','dashicons-businessman',array('title','editor','thumbnail')),
    array('businesses','Business','Businesses','dashicons-building',array('title','editor','thumbnail')),
    array('prices','Price List','Price Lists','dashicons-money', array('title')),
);

function cpts_register() {

    global $cpts;

    foreach($cpts as $cpt){

        $cpt_wp_name = $cpt[0];
        $cpt_singular = $cpt[1];
        $cpt_plural = $cpt[2];
        $cpt_image = $cpt[3];
        $cpt_suports = $cpt[4];

        $labels = array(
        'name' => _x($cpt_plural, 'post type general name'),
        'singular_name' => _x($cpt_singular, 'post type singular name'),
        'add_new' => _x('Add New', $cpt_wp_name),
        'add_new_item' => __('Add New '.$cpt_singular),
        'edit_item' => __('Edit '.$cpt_singular),
        'new_item' => __('New '.$cpt_singular),
        'view_item' => __('View '.$cpt_singular),
        'search_items' => __('Search '.$cpt_plural),
        'not_found' =>  __('No '.$cpt_plural.' Found'),
        'not_found_in_trash' => __('No '.$cpt_plural.' Found in Trash'), 
        'parent_item_colon' => '',
      );
      $args = array(
        'labels' => $labels,
        'public' => true,
        'show_ui' => true,
        'publicly_queryable' => true,
        'query_var' => true,
        'capability_type' => 'post',
        'hierarchical' => false,
        'rewrite' => true,
        'show_in_rest' => true,
        'supports' => $cpt_suports,
        'menu_icon'   => $cpt_image,
        );

        register_post_type($cpt_wp_name, $args );

    }

}

Thanks in advance for your help...

M

Answer 1

Theme files are included by functions so you also need to declare global $cpts where you assign it. It won't be global automatically.

Answer 2

One fix is to check the variable’s type first

$items = $product->getFormats();

if (is_array($items)) {
    foreach ($items as $item) {
     // ...
    }
}