JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="http://netdna.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="http://silviomoreto.github.io/bootstrap-select/bootstrap-select.min.js"></script>
<link rel="stylesheet" href="http://silviomoreto.github.io/bootstrap-select/bootstrap-select.min.css">
<select class="selectpicker" multiple>
    <option>Mustard</option>
    <option>Ketchup</option>
    <option>Relish</option>
</select>

</br>
</br></br>
</br>
</br>
</br>
</br></br>
</br>
</br>
<a class="btn_clk">test</a>

JavaScript

$('.selectpicker').selectpicker();


$(".btn_clk").click(function () {
    $('.selectpicker').selectpicker('selectAll');
});