Slide toggle, check if slide is open

toggle.js

    $(document).on('click', '.mobile_phones-box', function() {
        $('.phone').slideToggle(400, function (){
            if ($(this).is(':hidden')) {
                console.log("closed");
            } else {
                $('body, html').animate({ scrollTop: 0 }, 300);
                console.log("open");
            }
        });
    });