<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<form>
<input type="file" id="file-upload" multiple required />
<label for="file-upload">Upload file</label>
<div id="file-upload-filename"></div>
</form>
var input = document.getElementById( 'file-upload' );
var infoArea = document.getElementById( 'file-upload-filename' );
input.addEventListener( 'change', showFileName );
function showFileName( event ) {
// the change event gives us the input it occurred in
var input = event.srcElement;
// the input has an array of files in the `files` property, each one has a name that you can use. We're just using the name here.
var fileName = input.files[0].name;
// use fileName however fits your app best, i.e. add it into a div
infoArea.textContent = 'File name: ' + fileName;
}