/* Front end */
show_admin_bar( false );

/* back end */
function disableAdminBar(){
    remove_action( \'admin_footer\', \'wp_admin_bar_render\', 1000 );  
    function remove_admin_bar_style_backend() {  
        echo \'<style>body.admin-bar #wpcontent, body.admin-bar #adminmenu { padding-top: 0px !important; }</style>\';
    }  
    add_filter(\'admin_head\',\'remove_admin_bar_style_backend\');  
}
add_action(\'init\', \'disableAdminBar\');