exemple on w3school. navbar in Css does not display list item

Question

Its is example on w3school.

I don't understand why if I add position:relative on ancestor class of dropDown-content.

Navbar does not display dropdown item and an element with position: absolute; is positioned relative to the nearest positioned ancestor, but without position:relative, is till not positioned body tag as ancestor?

Is there any way to solve this?

<!DOCTYPE html>
<html>
<head>
<style>
ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}

li {
  float: left;
}

li a, .dropbtn {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

li a:hover, .dropdown:hover .dropbtn {
  background-color: red;
}

li.dropdown {
  display: inline-block;
  position:relative;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {background-color: #f1f1f1;}

.dropdown:hover .dropdown-content {
  display: block;
}
</style>
</head>
<body>

<ul>
  <li><a href="#home">Home</a></li>
  <li><a href="#news">News</a></li>
  <li class="dropdown">
    <a href="javascript:void(0)" class="dropbtn">Dropdown</a>
    <div class="dropdown-content">
      <a href="#">Link 1</a>
      <a href="#">Link 2</a>
      <a href="#">Link 3</a>
    </div>
  </li>
</ul>

<h3>Dropdown Menu inside a Navigation Bar</h3>
<p>Hover over the "Dropdown" link to see the dropdown menu.</p>

</body>
</html>

enter image description here

https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_dropdown_navbar — JGFMK, Dec 28 '19 at 14:32
[Overflow hidden hides dropdown, but taking overflow hidden off hide navigation background](https://stackoverflow.com/q/23553363/4516316) — Arun A S, Dec 28 '19 at 14:41
w3school is not the best learning resource. They used to be full of errors and false information, and while they improved many things, there are still examples containing things that you should not do. `href="javascript:void(0)"` is an example for something you should not do. — t.niese, Dec 28 '19 at 22:05

score 0 · Answer 1 · answered Dec 28 '19 at 14:42

As per this post, the child element of a relative parent should have position: fixed

Add

.dropdown-content {
  position: fixed;
}

That will work for you.

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}

li {
  float: left;
}

li a, .dropbtn {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

li a:hover, .dropdown:hover .dropbtn {
  background-color: red;
}

li.dropdown {
  display: inline-block;
  position:relative;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
  position: fixed;
}

.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {background-color: #f1f1f1;}

.dropdown:hover .dropdown-content {
  display: block;
}

<ul>
  <li><a href="#home">Home</a></li>
  <li><a href="#news">News</a></li>
  <li class="dropdown">
    <a href="javascript:void(0)" class="dropbtn">Dropdown</a>
    <div class="dropdown-content">
      <a href="#">Link 1</a>
      <a href="#">Link 2</a>
      <a href="#">Link 3</a>
    </div>
  </li>
</ul>

<h3>Dropdown Menu inside a Navigation Bar</h3>
<p>Hover over the "Dropdown" link to see the dropdown menu.</p>

exemple on w3school. navbar in Css does not display list item

1 Answers1