Remove default WordPress Dashboard widgets (WordPress 4.0)

gistfile1.php

function mytheme_remove_dashboard_widgets()
{
    $widgets = array(
        'dashboard_incoming_links' => 'normal',
        'dashboard_right_now' => 'normal',
        'dashboard_plugins' => 'normal',
        'dashboard_recent_comments' => 'normal',
        'dashboard_activity' => 'normal',
        'dashboard_quick_press' => 'side',
        'dashboard_primary' => 'side',
        'dashboard_secondary' => 'side',
        'dashboard_recent_drafts' => 'side',
    );

    foreach ($widgets as $id => $context) {
        remove_meta_box($id, 'dashboard', $context);
    }
    
}

add_action('wp_dashboard_setup', 'mytheme_remove_dashboard_widgets');