Typeis.js playground
HTML
<script src="https://rawgit.com/typeis/typeisjs/master/dist/typeis.min.js"></script>
<input type="text" id="content" value="[]">
<button id=getType>typeis</button>
<p class='info'>try this "{}", "/test/g", "new Date()" etc.</p>
CSS
.info {
color: #666;
}
JavaScript
let btn = document.querySelector('#getType');
btn.onclick = e => {
let something = eval(`(${document.querySelector('#content').value})`);
alert(something.typeis());
}