How to get element class using jquery

This is a tutorial of getting <strong>element class using jquery</strong>

HTML

<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<select id="speed">
<option value="1000">Slow (50 combos ~ 1min)</option>
<option value="500">Normal (100 combos ~ 1min)</option>
<option selected value="0">Fast (300 combos ~ 1min)</option>
<option value="">Turbo (1000 combos ~ 1min)</option>
</select>

JavaScript

$(document).ready(function(){
var speed = $('#speed').val();
alert(speed);}