I have a navbar in Bootstrap that does not open in mobile view (there is the menu icon but when clicked no items are being shown)
My HTML code of the navbar is:
<header class="header_area">
<div class="main-menu">
<nav class="navbar navbar-expand-lg navbar-light">
<a class="navbar-brand" href="#"><img src="img/logo.png"></a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<div class="me-auto"></div>
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">About</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Services</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Protfolio</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Pages</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</nav>
</div>
</header>
I am new to bootstrap and would much appreciate your assistance on this one.
Thanks!
Your code works fine. So i think the problem is that you are not using the bootstrap CDNs properly.
Copy the below CDNs and paste them into your code.
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</head>
And if you are not using CDN and are using the downloaded files then please check your paths properly i.e, did you got the files correctly in your code.
It works perfectly on my side. I think, the problem is you forget to attach the script for the javascript to work.
as stated in Bootstrap Introduction Page, you need to enter this link tag for the CSS
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
and for the functionality to work, you require javascript. Try adding this to your project, before the closing body tag </body>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
It's working fine, check whether you have added these links:
place this link in the head section:
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
And place these links near the end of the body section:
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
Related
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.3.0/css/all.min.css" integrity="sha512-SzlrxWUlpfuzQ+pcUCosxcglQRNAq/DZjVsC0lE40xsADsfeQoEypE+enwcOiGjk/bSuGGKHEyjSoQ1zVisanQ==" crossorigin="anonymous" referrerpolicy="no-referrer" />
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap#4.0.0/dist/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js#1.12.9/dist/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#4.0.0/dist/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
<div class="dropdown">
<i
class="far fa-user-circle ml-4"
type="button"
data-toggle="dropdown"
aria-expanded="false"
style="font-size:36px"></i>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Profile</a>
<a class="dropdown-item" href="#">Change Password</a>
<a class="dropdown-item" href="#">Logout</a>
</div>
</div>
I want to fit the dropdown menu inside the screen
Your dropdown do not have the .dropdown-menu-right, if you want to align your dropdown at the right please add this class 👍
https://getbootstrap.com/docs/4.0/components/dropdowns/#menu-alignment
Quick question. When I click the hamburger button in bootstrap, the content doesn't slide down. I was following a tutorial on it, and couldn't tell what I was missing on this. Am I missing something in the button tag? Everything else is working fine. Any ideas?
Thanks!
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Schenck Guitars</title>
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=VT323&display=swap" rel="stylesheet">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<link href="css/style.css" rel="stylesheet" type="text/css"/>
</head>
<body>
<div class="nav-container">
<nav class="navbar navbar-expand-md navbar-light">
Bootstrap 5
<button
class="navbar-toggler"
type="button"
data-bs-toggle="collapse"
data-bs-target="#toggleMobileMenu"
aria-controls="toggleMobileMenu"
aria-expanded="false"
aria-label="Toggle navigation"
>
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="toggleMobileMenu">
<ul class="navbar-nav">
<li>
<a class="nav-link" href="#">Pricing</a>
</li>
<li>
<a class="nav-link" href="#">Features</a>
</li>
<li>
<a class="nav-link" href="#">Gallery</a>
</li>
<li>
<a class="nav-link" href="#">Portfolio</a>
</li>
<li>
<a class="nav-link" href="#">Resources</a>
</li>
<li>
<a class="nav-link" href="#">Suppert</a>
</li>
<li>
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</nav>
</div>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
<script src="js/scripts.js"></script>
</body>
</html>
You are mixing bootstrap 4 and 5. I changed this (which is syntax for BS 5):
data-bs-toggle="collapse"
data-bs-target="#toggleMobileMenu"
to this (which is syntax for BS 4):
data-toggle="collapse"
data-target="#toggleMobileMenu"
You can of course go the other direction and switch to BS 5 CDN.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Schenck Guitars</title>
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=VT323&display=swap" rel="stylesheet">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<link href="css/style.css" rel="stylesheet" type="text/css"/>
</head>
<body>
<div class="nav-container">
<nav class="navbar navbar-expand-md navbar-light">
Bootstrap 5
<button
class="navbar-toggler"
type="button"
data-toggle="collapse"
data-target="#toggleMobileMenu"
aria-controls="toggleMobileMenu"
aria-expanded="false"
aria-label="Toggle navigation"
>
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="toggleMobileMenu">
<ul class="navbar-nav">
<li>
<a class="nav-link" href="#">Pricing</a>
</li>
<li>
<a class="nav-link" href="#">Features</a>
</li>
<li>
<a class="nav-link" href="#">Gallery</a>
</li>
<li>
<a class="nav-link" href="#">Portfolio</a>
</li>
<li>
<a class="nav-link" href="#">Resources</a>
</li>
<li>
<a class="nav-link" href="#">Suppert</a>
</li>
<li>
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</nav>
</div>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
<script src="js/scripts.js"></script>
</body>
</html>
I am having trouble right aligning elements in my navbar with bootstrap. For some reason, the elements seemed fixed and even using an external css file did not help. The look im aiming for is keeping the logo and name or "brand" on the left, with the rest of the 'items' right-aligned. For some reason, the 'ml-auto' class of bootstrap is not working either.
HTML:
.navbar-nav {
margin-left: auto;
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="index.css">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</head>
<body>
<div class="navbar" width="100%">
<nav class="navbar navbar-expand-lg navbar-light">
<div class="container-fluid">
<a class="navbar-brand" href="#">
<img
src="/com_connect_font.png"
class="me-2"
height="70"
alt=""
loading="lazy"
/>
<medium>Community Connector</medium>
</a>
<button
class="navbar-toggler"
type="button"
data-mdb-toggle="collapse"
data-mdb-target="#navbarNav"
aria-controls="navbarNav"
aria-expanded="false"
aria-label="Toggle navigation"
>
<i class="fas fa-bars"></i>
</button>
<ul class="navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link" href="#">
About
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">
Contacts
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">
Settings
</a>
</li>
</ul>
</div>
</nav>
</div>
</body>
</html>
Could someone share what might be the issue? Any help is appreciated.
Small example. Only bootstrap classes without any additional CSS. In your example, the first div destroys the nav because it's not 100% wide. Btw here's another example. In your navbar the whole mobile view is broken. The example below is completely working with desktop and mobile devices.
Hopefully it will work :)
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="index.css">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="d-flex flex-grow-1">
<span class="w-100 d-lg-none d-block"><!-- hidden spacer to center brand on mobile --></span>
<a class="navbar-brand" href="#">
Navbar 7
</a>
<div class="w-100 text-right">
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#myNavbar7">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</div>
<div class="collapse navbar-collapse flex-grow-1 text-right" id="myNavbar7">
<ul class="navbar-nav ml-auto flex-nowrap">
<li class="nav-item">
Link
</li>
<li class="nav-item">
Link
</li>
<li class="nav-item">
Link
</li>
<li class="nav-item">
Link
</li>
</ul>
</div>
</nav>
</body>
</html>
hope you are doing well, I am following Traversy media's Youtube tutorial on bootstrap 5 and when i've tried to get the nav toggler to open but the nav is not showing. i'm not sure what I am doing wrong
This is the video: https://www.youtube.com/watch?v=4sosXZsdy-s the navbar section time stamp is 6:45 to 14:06
<!-- Bootstrap 5 libraries -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons#1.3.0/font/bootstrap-icons.css">
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js#1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<!--navbar-->
<nav class="navbar navbar-expand-lg bg-dark navbar-dark py-3 fixed-top">
<div class="container">
Frontend bootcamp
<button class="navbar-toggler" data-bs-toggle="collapse" data-bs-target="#navbar">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse">
<ul class="navbar-nav ms-auto" id="navbar">
<li class="nav-item">
What you'll learn
</li>
<li class="nav-item">
Questions
</li>
<li class="nav-item">
Instructors
</li>
</ul>
</div>
</div>
</nav>
Here you have a working example. I did take the <button> element from bootstraps example and moved id="navbar" from <ul> to <div> element.
<!-- Bootstrap 5 libraries -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons#1.3.0/font/bootstrap-icons.css">
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js#1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<!--navbar-->
<nav class="navbar navbar-expand-lg bg-dark navbar-dark py-3 fixed-top">
<div class="container">
Frontend bootcamp
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar" aria-controls="navbar" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbar">
<ul class="navbar-nav ms-auto" >
<li class="nav-item">
What you'll learn
</li>
<li class="nav-item">
Questions
</li>
<li class="nav-item">
Instructors
</li>
</ul>
</div>
</div>
</nav>
I'm new to bootstrap and I was trying to create a navbar, the problem is that when I opened the live server to see how it was going, this appeared on the screen:enter image description here
Instead of this which was I expecting:
enter image description here
So, can you help me please?
Here is my code:
<html>
<head>
<meta charset="utf-8">
<title></title>
<link rel="stylesheet" href="css/styles.css">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="">brand</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarTogglerDemo02">
<ul class="navbar-nav ms-auto">
<li class="nav-item">
<a class="nav-link" href="">Contact</a>
</li>
<li class="nav-item">
<a class="nav-link" href="">Pricing</a>
</li>
<li class="nav-item">
<a class="nav-link" href="">Download</a>
</li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</body>
</html>
You should use Boostrap version 4.3.1 because the classes you're using seem to belong to that version. This works:
<html>
<head>
<meta charset="utf-8">
<title></title>
<link rel="stylesheet" href="css/styles.css">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="">brand</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarTogglerDemo02">
<ul class="navbar-nav ms-auto">
<li class="nav-item">
<a class="nav-link" href="">Contact</a>
</li>
<li class="nav-item">
<a class="nav-link" href="">Pricing</a>
</li>
<li class="nav-item">
<a class="nav-link" href="">Download</a>
</li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</body>
</html>
You are using version 3.4.1 of bootstrap, all you have to do is to replace the bootstrap link with one of these versions v4.0.0 or 4.1.x
cdn link available on this page: https://getbootstrap.com/docs/4.0/getting-started/introduction/