Question

I am looking for a pretty easy way to check when somebody clicks a link that it’s valid.

Good

 <a href="index.html">some link</a>

Bad:

<a href="#">some link</a>
<a href="javascript:void(0);">some link</a>

Answer 1

Just check for the href value:

$('a').click(function(){
  var bad = this.href.lastIndexOf('#') >= 0 || this.href.indexOf('javascript') >= 0;
  alert(bad ? 'Bad' : 'Good');
  return false;
});

Demo