<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">
<div class="row">
<div id="demo">
<div class="col-md-6 col-md-offset-3">
<button
class="btn btn-primary"
@click="show = !show">
Show
</button>
</div>
<br><br>
<transition name="fade">
<div class="alert alert-info" v-if="show">
Howdy! How cool is VueJS ?
</div>
</transition>
</div>
</div>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue@2.6.9/dist/vue.js"></script>
<script>
new Vue({
el: '#demo',
data: {
show: false
}
})
</script>
