title: Adding class to element using Angular JS
body: <p>I know how to add a class on click of a button in 'jQuery'</p>
  
  <pre><code>$('#button1').click(function(){
   $('#div1').addClass('alpha');
  });
  </code></pre>
  
  <p>I want to achieve same thing by angular js. I have a controller - myController1. Can someone help me do it eazily?</p>