Hello I made 2 scripts for scrolling, one make navbar smaller second one show the button for going on start of page. When I added second one (for button) my first one for navbar didn't work. I deleted second one and it worked. What I need to change?

For navbar

        window.onscroll = function() {
  var el = document.getElementsByClassName('header')[0];
  var className = 'small';
  if (el.classList) {
    if (window.scrollY > 10)
      el.classList.add(className);
    else
      el.classList.remove(className);
  }
};

        window.smoothScroll = function(target) {
    var scrollContainer = target;
    do { //find scroll container
        scrollContainer = scrollContainer.parentNode;
        if (!scrollContainer) return;
        scrollContainer.scrollTop  = 1;
    } while (scrollContainer.scrollTop == 0);

    var targetY = 0;
    do { //find the top of target relatively to the container
        if (target == scrollContainer) break;
        targetY  = target.offsetTop;
    } while (target = target.offsetParent);

    scroll = function(c, a, b, i) {
        i  ; if (i > 30) return;
        c.scrollTop = a   (b - a) / 30 * i;
        setTimeout(function(){ scroll(c, a, b, i); }, 20);
    }
    // start scrolling
    scroll(scrollContainer, scrollContainer.scrollTop, targetY, 0);
}

For button

//Get the button
var mybutton = document.getElementById("myBtn");

// When the user scrolls down 20px from the top of the document, show the button
window.onscroll1 = function() {scrollFunction()};

function scrollFunction() {
  if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
    mybutton.style.display = "block";
  } else {
    mybutton.style.display = "none";
  }
}

// When the user clicks on the button, scroll to the top of the document
function topFunction() {
  document.body.scrollTop = 0;
  document.documentElement.scrollTop = 0;
}

HTML

     <button onclick="topFunction()" id="myBtn" title="Go to top">Top</button>  
        
  <div class="header">
    <div class="container">
      <ul class="nav">
        <li><a href="#">Home</a></li>
      </ul>
    </div>
  </div>

CodePudding user response：

Just comment the second window.onscroll = function() {scrollFunction()}; from your button and add the scrollFunction(); in your navbar window.onscroll, your initial code had a extra 1 at the window.onscroll1 but you don't need to set it twice, test it out, I've added some CSS so the button stay at the bottom right and some height to test scrolling

window.onscroll = function () {
  scrollFunction();
  var el = document.getElementsByClassName("header")[0];
  var className = "small";
  if (el.classList) {
    if (window.scrollY > 10) el.classList.add(className);
    else el.classList.remove(className);
  }
};

window.smoothScroll = function (target) {
  var scrollContainer = target;
  do {
    //find scroll container
    scrollContainer = scrollContainer.parentNode;
    if (!scrollContainer) return;
    scrollContainer.scrollTop  = 1;
  } while (scrollContainer.scrollTop == 0);

  var targetY = 0;
  do {
    //find the top of target relatively to the container
    if (target == scrollContainer) break;
    targetY  = target.offsetTop;
  } while ((target = target.offsetParent));

  scroll = function (c, a, b, i) {
    i  ;
    if (i > 30) return;
    c.scrollTop = a   ((b - a) / 30) * i;
    setTimeout(function () {
      scroll(c, a, b, i);
    }, 20);
  };
  // start scrolling
  scroll(scrollContainer, scrollContainer.scrollTop, targetY, 0);
};

//Get the button
var mybutton = document.getElementById("myBtn");

// When the user scrolls down 20px from the top of the document, show the button
//window.onscroll1 = function() {scrollFunction()};

function scrollFunction() {
  if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
    mybutton.style.display = "block";
  } else {
    mybutton.style.display = "none";
  }
}

// When the user clicks on the button, scroll to the top of the document
function topFunction() {
  document.body.scrollTop = 0;
  document.documentElement.scrollTop = 0;
}

.container {
  height: 1999px;
}
#myBtn  {
  position: fixed;
  bottom: 0;
  right: 0;
  display: none;
}

<button onclick="topFunction()" id="myBtn" title="Go to top">Top</button>

<div class="header">
  <div class="container">
    <ul class="nav">
      <li><a href="#">Home</a></li>
    </ul>
  </div>
</div>

CodePudding user response：

I found another solution

Something like this

var mybutton = document.getElementById("myBtn");
    
        window.onscroll = function() {scrollFunction()};{
  function scrollFunction() {
        var el = document.getElementsByClassName('header')[0];
  // Vrh button prikazivanje
  var className = 'small';
  if (el.classList) {
    if (window.scrollY > 10)
      el.classList.add(className);
    else
      el.classList.remove(className);
  }
  if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
    mybutton.style.display = "block";
  } else {
    mybutton.style.display = "none";
  }
}
};

        window.smoothScroll = function(target) {
    var scrollContainer = target;
    do { //find scroll container
        scrollContainer = scrollContainer.parentNode;
        if (!scrollContainer) return;
        scrollContainer.scrollTop  = 1;
    } while (scrollContainer.scrollTop == 0);

    var targetY = 0;
    do { //find the top of target relatively to the container
        if (target == scrollContainer) break;
        targetY  = target.offsetTop;
    } while (target = target.offsetParent);

    scroll = function(c, a, b, i) {
        i  ; if (i > 30) return;
        c.scrollTop = a   (b - a) / 30 * i;
        setTimeout(function(){ scroll(c, a, b, i); }, 20);
    }
    // start scrolling
    scroll(scrollContainer, scrollContainer.scrollTop, targetY, 0);
}