SO - 16162928

by Arun P Johny

HTML

<button class="A" onclick="myFunction(this)">A</button>
<button class="B" onclick="myFunction(this)">B</button>
<button class="C" onclick="myFunction(this)">C</button>
<button class="D" onclick="myFunction(this)">D</button>

JavaScript

function myFunction(el) {
    alert (el.className);
}