dropdown navbar at bootstrap 3 not working - twitter-bootstrap-3

Question

anybody can help me?, why my dropdown at navbar not working on localhost?
this is my navbar
<nav class="navbar navbar-default navbar-fixed-top" role="navigation">
<div class="container-fluid theme-showcase" style="background-color: #87cefa;">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle Navigator</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="index.php" style="background-color: #fff;"><img src="asset/logo_header.png" style="max-width:100%;max-height:100%;"></a>
</div>
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav style">
<li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"
aria-expanded="false">Category<span class="caret"></span></a>
<ul class="dropdown-menu">
<li>action</li>
<li>action</li>
<li>action</li>
</ul>
</li>
</ul>
<form class="navbar-form"><button type="button" class="btn btn-default" role="button">Login</button>
</form>
</div>
</div>
</nav>
this is my include css on the page
<link rel="icon" href="asset/logo_header.png">
<link href="css/bootstrap.css" rel="stylesheet">
<link href="css/bootstrap-theme.css" rel="stylesheet">
<link href="css/style.css" rel="stylesheet">
this is my include javascript on the page
<script type="text/javascript" src="js/jquery-3.2.1.min.js"></script>
<script src="js/bootstrap.js"></script>
<script src="js/bootstrap.min.js"></script>

Answer 1

Recheck the paths to your external js and style files. They may not be applying correctly. In the example below I used the Bootstrap CDNs and everything seems to be working as expected.
<link href="css/bootstrap.css" rel="stylesheet">
change to
<link href="css/bootstrap.min.css" rel="stylesheet">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script> // use this jquery instead
<script src="js/bootstrap.js"></script> // remove not needed if you are using the below line.
<script src="js/bootstrap.min.js"></script>
Also, created a fiddle for review.
Let me know if that helps
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
<!-- HTML BEGINS -->
<nav class="navbar navbar-default navbar-fixed-top" role="navigation">
<div class="container-fluid theme-showcase" style="background-color: #87cefa;">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle Navigator</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="index.php" style="background-color: #fff;">Brand Image</a>
</div>
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav style">
<li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"
aria-expanded="false">Category<span class="caret"></span></a>
<ul class="dropdown-menu">
<li>action</li>
<li>action</li>
<li>action</li>
</ul>
</li>
</ul>
<form class="navbar-form"><button type="button" class="btn btn-default" role="button">Login</button>
</form>
</div>
</div>
</nav>