Why is Navbar Collapse button always showing on my webpage? - html

<nav class="navbar navbar-expand-lg navbar-expand-md sticky-top">
<div class="container-fluid">
<a class="navbar-brand" href="index.html">Website </a>
<button class="navbar-toggle collapsed " data-toggle="collapse" data-target="#navbarNavDropdown" aria-expanded="false">
<i class="fa fa-bars"></i>
</button>
<div class="collapse navbar-collapse justify-content-end" id="navbarNavDropdown">
<ul class="nav navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="index.html"> Home </a>
</li>
<li class="nav-item">
<a class="nav-link" href="link1.html"> Link1</a>
</li>
<li class="nav-item">
<a class="nav-link" href="link2.html"> Link2</a>
</li>
</ul>
</div>
</div>
</nav>
The button which is supposed to show up only when window is resized to small size, is always showing on the right of the Website name. It is looking ugly in fullscreen, that is, while viewing in computer mode. I want to remove it from showing in high resolution devices. Tell me where am I making mistake.

Because the correct class name for the Bootstrap 4 Navbar is navbar-toggler, not navbar-toggle.
<nav class="navbar navbar-light navbar-expand-lg navbar-expand-md sticky-top">
<div class="container-fluid">
<a class="navbar-brand" href="index.html">Website </a>
<button class="navbar-toggler" data-toggle="collapse" data-target="#navbarNavDropdown" aria-expanded="false">
<i class="fa fa-bars"></i>
</button>
<div class="collapse navbar-collapse justify-content-end" id="navbarNavDropdown">
<ul class="nav navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="index.html"> Home </a>
</li>
<li class="nav-item">
<a class="nav-link" href="link1.html"> Link1</a>
</li>
<li class="nav-item">
<a class="nav-link" href="link2.html"> Link2</a>
</li>
</ul>
</div>
</div>
</nav>
https://www.codeply.com/go/9uKT2H0EgP

Only use class navbar-expand-sm if you want the icon to show up only on narrow viewports. Find an overview in the documentation. Also you use a wrong class for the hamburger icon: class="navbar-toggler", like
Zim already said.
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap 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">
<title>Hello, world!</title>
</head>
<body>
<nav class="navbar navbar-expand-sm navbar-dark bg-dark">
<a class="navbar-brand" href="#">Expand at sm</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExample03" aria-controls="navbarsExample03" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarsExample03">
<ul class="navbar-nav mr-auto">
<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="#">Link</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Disabled</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="https://example.com" id="dropdown03" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu" aria-labelledby="dropdown03">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
</ul>
<form class="form-inline my-2 my-md-0">
<input class="form-control" type="text" placeholder="Search">
</form>
</div>
</nav>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<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>

Related

My bootstrap 4 dropdown doesn't work and I'm not sure how to resolve it

I'm very new to HTML and have been struggling to get my dropdown to work for a few hours now. I've searched many posts facing similar issues but I still can't find and resolve the issue. I'm unsure if the issue is caused by my scripts as well
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
<header class="navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="#" id="logo">Logo</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent">
<span class="navbar-toggler-icon"></span>
</button>
<nav class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item"><a class="nav-link active" href="#">Home <span class="sr-only">(current)</span></a></li>
<li class="nav-item"><a class="nav-link" href="#">Link</a></li>
<li class="nav-item">
<div class="dropdown">
Dropdown
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
Action
Another action
<div class="dropdown-divider"></div>
Something else here
</div>
</div>
</li>
<li class="nav-item"><a class="nav-link" href="#">Disabled</a></li>
</ul>
</nav>
</header>
Thanks in advance!
I tried replacing data-toggle="dropdown" with data-bs-toggle="dropdown" but it didn't work since I'm using bootstrap 4, copied and pasted the codes directly from bootstrap and it still failed
The CDN isn't working for your jQuery. Bootstrap needs this to run. You get a clue for this in your console, there should be an error saying that it needed jQuery. So you can:
Replace this
https://ajax.googleleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js
With this
https://code.jquery.com/jquery-3.6.1.min.js
You need to add bootstrap jQuery
use this code snippet for done
HTML Code
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/css/bootstrap.min.css">
<title>Hello, world!</title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent"
aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<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="#">Link</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button"
data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/js/bootstrap.bundle.min.js"></script>
</body>
</html>

Bootstrap 5 Navbar collapse and dropdown

I'm having a little trouble with my navbar, using bootstrap 5. The navbar doesn't collapse after expanding and the dropdown list doesn't drop.
<!-- Bootstrap-5 -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<!-- Body -->
<nav class="navbar navbar-expand-md bg-light sticky-top">
<div class="container-fluid ">
<a class="navbar-brand" href="#"><img class="" width="100px" src="icons/cake/Asset 4.png"></a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#collapsibleNavbar">
<span class="fa fa-navicon"></span>
</button>
<div class="collapse navbar-collapse justify-content-end" id="collapsibleNavbar">
<ul class="navbar-nav">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" href="#">SERVICES</a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Delivery</a></li>
<li>
<a class="dropdown-item" href="#">Event Planning</a>
</li>
</ul>
</li>
<li class="nav-item">
<a class="nav-link" href="#">CONTACT</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#"><button class="btn btn-danger">ORDER ONLINE</button></a>
</li>
</ul>
</div>
</div>
</nav>
Many of Bootstrap's components require the use of JavaScript to function. Including navbars and dropdowns. I added the relevant source for both font-awesome and the Bootstrap JS.
Read more here on Bootstrap 5 Introduction.
<head>
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
<script src="https://cdn.jsdelivr.net/npm/bootstrap#5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
</head>
<nav class="navbar navbar-expand-md bg-light sticky-top">
<div class="container-fluid ">
<a class="navbar-brand" href="#"><img class="" width="100px" src="icons/cake/Asset 4.png"></a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#collapsibleNavbar">
<span class="fa fa-navicon"></span>
</button>
<div class="collapse navbar-collapse justify-content-end" id="collapsibleNavbar">
<ul class="navbar-nav">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" href="#">SERVICES</a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Delivery</a></li>
<li>
<a class="dropdown-item" href="#">Event Planning</a>
</li>
</ul>
</li>
<li class="nav-item">
<a class="nav-link" href="#">CONTACT</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#"><button class="btn btn-danger">ORDER ONLINE</button></a>
</li>
</ul>
</div>
</div>
</nav>

Change Mediaquery response

I'm starting my studies in fullstack and we were just shown bootstrap. I'm doing this site responsive, and I modified the menu bar to my please. The only thing I'd like to change is the menu to colapse into the toggle button only below 600px-ish wide (aka for phones). Any assistance will be appreciated
html
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<div class="container-fluid">
<a class="navbar-brand" href="#"></a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarScroll" aria-controls="navbarScroll" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarScroll">
<ul class="navbar-nav me-auto my-2 my-lg-0 navbar-nav-scroll" style="--bs-scroll-height: 100px;">
<li class="nav-item">
<a class="nav-link active" aria-current="page" href="#">Inicio</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Academia</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Tienda</a>
<li class="nav-item">
<a class="nav-link" href="#">Nosotros</a>
<li class="nav-item">
<a class="nav-link" href="#">Contacto</a>
</ul>
</div>
</div>
</nav>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#5.1.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
</body>
As mentioned in the How it works section of Bootstrap navbar documentation, you can use navbar-expand-sm instead of navbar-expand-lg. This will collapse the navbar only on screens smaller than 576px(sm).

Bootstrap Navbar toggle icon button not showing nav items on click?

I have been using bootstrap in projects very smoothly, but then in one angular project, its navbar toggler icon button is appearing but not showing the nav items on clicking the button.
<div>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="#">Admin Header</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarResponsive"
aria-controls="navbarResponsive" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarResponsive">
<ul class="navbar-nav ml-auto">
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./home">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./about">About</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./services">Services</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./contact">Contact</a>
</li>
<li class=" btn-primary nav-item text-white" role="button">
<a class="nav-link text-white" (click)="logOut()" >logout</a>
</li>
</ul>
</div>
</div>
</nav>
</div>
This is the Navbar result:
On decreasing the width of the browser we have results something like this:
below is the code of index.html:
But on clicking on this button I am not able to see any nav items.
Works perfectly fine, you must be missing some script files.
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<title>Hello, world!</title>
</head>
<body>
<div>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="#">Admin Header</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarResponsive" aria-controls="navbarResponsive" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarResponsive">
<ul class="navbar-nav ml-auto">
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./home">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./about">About</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./services">Services</a>
</li>
<li class="nav-item" routerLinkActive="active">
<a class="nav-link" routerLink="./contact">Contact</a>
</li>
<li class=" btn-primary nav-item text-white" role="button">
<a class="nav-link text-white" (click)="logOut()">logout</a>
</li>
</ul>
</div>
</div>
</nav>
</div>
<!-- JavaScript -->
<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://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>

Bootstrap navbar toggle is not working (expanding)

I am struggling with my navbar that was made out of HTML CSS and Bootstrap. I had followed some tutorials on youtube but I can seem to expand the toggle button when the screen size is reduced to the smallest. Since I'm starting a new project, I applied all of this with HTML CSS, and Bootstrap and opened the HTML file in my local directory. Please help me! I have been stuck for hours.
Below are the codes that I did:
<head>
<meta charset="UTF-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<meta http-equiv="X-UA-Compatible" content="ie=edge"/>
<script src="https://code.jquery.com/jquery-3.5.1.js"></script>
<link rel="stylesheet" href="bootstrap.min.css"/>
<link rel="stylesheet" href="title.css" />
<title>Document</title>
</head>
<body>
<nav class="navbar navbar-expand-md navbar-light bg-light sticky-top">
<button class="navbar-toggler" data-toggle="collapse" data-target="#collapse_target">
<span class="navbar-toggler-icon></span>
</button>
<div class="collapse navbar-collapse" id="collapse_target">
<a class="navbar-brand>Logo</a>
<ul class="navbar-nav">
<li class="nav-item">
<a class="nav-link href="#">Link 1</a>
</li>
<li class="nav-item">
<a class="nav-link href="#">Link 2</a>
</li>
<li class="nav-item">
<a class="nav-link href="#">Link 3</a>
</li>
</ul>
</div>
</nav>
</body>
My results are as below:
I will get the toggler icon as above but I will not be able to click it and get 'Home', 'Categories', 'About', and 'Contact'. I don't know where I did wrong.
Thank you for your time.
You missed JS, their CDN is available in getbootstrap.com
I add two responsive navbar in the following. These codes are used from getbootstrap.com
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/css/bootstrap.min.css" integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2" crossorigin="anonymous">
<title>Document</title>
</head>
<body>
<nav class="navbar navbar-expand-sm navbar-dark bg-dark">
<a class="navbar-brand" href="#">Expand at sm</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExample03" aria-controls="navbarsExample03" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarsExample03">
<ul class="navbar-nav mr-auto">
<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="#">Link</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="dropdown03" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu" aria-labelledby="dropdown03">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
</ul>
<form class="form-inline my-2 my-md-0">
<input class="form-control" type="text" placeholder="Search">
</form>
</div>
</nav>
<hr class"m-5">
<nav class="navbar navbar-expand-xl navbar-dark bg-dark">
<a class="navbar-brand" href="#">Expand at xl</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExample06" aria-controls="navbarsExample06" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarsExample06">
<ul class="navbar-nav mr-auto">
<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="#">Link</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="dropdown06" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu" aria-labelledby="dropdown06">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
</ul>
<form class="form-inline my-2 my-md-0">
<input class="form-control" type="text" placeholder="Search">
</form>
</div>
</nav>
<!-- Optional JavaScript; choose one of the two! -->
<!-- Option 1: jQuery and Bootstrap Bundle (includes Popper) -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ho+j7jyWK8fNQe+A12Hb8AhRq26LrZ/JpcUGGOn+Y7RsweNrtN/tE3MoK7ZeZDyx" crossorigin="anonymous"></script>
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js#1.16.1/dist/umd/popper.min.js" integrity="sha384-9/reFTGAW83EW2RDu2S0VKaIzap3H66lZH81PoYlFhbGU+6BZp6G7niu735Sk7lN" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/js/bootstrap.min.js" integrity="sha384-w1Q4orYjBQndcko6MimVbzY0tgp4pWB4lZ7lr30WKz0vr/aWKhXdBNmNb5D92v7s" crossorigin="anonymous"></script>
</body>
</html>
Bootstrap requires JavaScript to function properly. You should add the scripts Bootstrap requires. Source: https://getbootstrap.com/docs/4.5/getting-started/introduction/#js
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ho+j7jyWK8fNQe+A12Hb8AhRq26LrZ/JpcUGGOn+Y7RsweNrtN/tE3MoK7ZeZDyx" crossorigin="anonymous"></script>
It looks like you are missing "type: button" in your button tag as seen below:
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#collapse_target">
Your problem in Javascript. Please add Boostrap JS into your code.
You can run this code to your page.
Example:
<html>
<head>
<meta charset="UTF-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<meta http-equiv="X-UA-Compatible" content="ie=edge"/>
<script src="https://code.jquery.com/jquery-3.5.1.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script>
<title>Document</title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light container">
<a class="navbar-brand" href="#">Boostrap</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Now<span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Can</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Use</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Donate Me</a>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Searching</button>
</form>
</div>
</nav>
</body>
</html>