滚动显示菜单，当菜单到达顶部时隐藏菜单

Question

您好我已经在向下滚动时显示导航菜单并在初始加载时隐藏它但在滚动回顶部后导航菜单仍然显示。

我还希望它在滚动到达顶部时隐藏。

这是我的

$(document).ready(function(){

/** ===========================================
    Hide / show the master navigation menu
============================================ */

  // console.log('Window Height is: ' + $(window).height());
  // console.log('Document Height is: ' + $(document).height());

  var previousScroll = 0;

  $(window).scroll(function(){

    var currentScroll = $(this).scrollTop();

    /*
      If the current scroll position is greater than 0 (the top) AND the current scroll position is less than the document height minus the window height (the bottom) run the navigation if/else statement.
    */

    if (currentScroll > 0 && currentScroll < $(document).height() - $(window).height()){
      /*
        If the current scroll is greater than the previous scroll (i.e we're scrolling down the page), hide the nav.
      */
      if (currentScroll > previousScroll){
        window.setTimeout(hideNav, 100);
      /*
        Else we are scrolling up (i.e the previous scroll is greater than the current scroll), so show the nav.
      */
      } else {
        window.setTimeout(showNav, 100);
      }
      /* 
        Set the previous scroll value equal to the current scroll.
      */
      previousScroll = currentScroll;
    }

  });


  function hideNav() {
    $("[data-nav-status='toggle']").removeClass("is-visible").addClass("is-hidden");
  }
  function showNav() {
    $("[data-nav-status='toggle']").removeClass("is-hidden").addClass("is-visible");
  }

});