Question

I need to loop through some elements in the page and then, for each one, if it had a class beginning with, for example, “C”, do something.

$('#dialog li').each(function(){
    if ($(this).hasClass("^C")){
         //do something
    }
}

It may sound silly, but what selector/method should I use on the if clause?

Answer 1

Carefull with $('#dialog li[class^="C"]')! It will only match elements, whose class attribute starts with “C” not ones with a class starting with C. For example it will not match <li class="foo Clown">.

AFAIK what you want is not possible mit jQuery alone. You would need to loop through the classes and check each separatly. Something like:

$('#dialog li').filter(function(){
  var classes = this.className.split(/\s/);
  for (var i = 0, len = classes.length; i < len; i++) 
    if (/^C/.test(classes[i])) return true;
  return false;
}).each( ... )

Alternativly you should consider changing your approach, and give all elements an additional class and filter by that. This has the addvantage that it can also be used in CSS:

<li class="Clown Clown-Funny">
<li class="Clown Clown-Sad">
<li class="Clown Clown-Rodeo">