<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/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 ---------->
<!DOCTYPE html>
<html>
<body>
<input type="text" id="tak">
<button onclick="addit()">add</button>
<ul id="disp"></ul>
</body>
<script>
var lav=[];
function addit(){
var lk= document.getElementById('tak').value
lav.push(lk);
var oi='';
for (var i=0;i<lav.length;i++){
oi+="<li>"+lav[i]+"</li>"
}
document.getElementById('disp').innerHTML=oi;
}
</script>
</html>