<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>
<div class="container"><h2>
prevent form submission (javascript)</h2>
<div class="row">
<form name="form1" onsubmit="return someFunc()">
<input type="text" name="text1" id="text1">
<button type="submit">Submit</button>
</form>
</div>
</div>
