A CodePen by Nitesh Kumar. Real time greeting. - Hello world app for jquery.

index.html

Enter your name :
<input id="name" type="text">
<h2 id='greeting'></h2>

script.js

$(function() { 
$('#name').keyup(function() {
 $('#greeting').text('hello ' + $('#name').val() + ' !');
           });
});