Great script, thanks! =)

Does anyone know how to fix that?

A quick way to do that with a regular expression would be :

$('p.someclass').each(function() {
  var original = $(this).html();
  $(this).html( original.replace(/-/g, '—') );
});

Keep in mind, though, that this will mess up IDs or class names that have hyphens in them, if they’re in those paragraphs. I don’t have time to work out how to avoid that at the moment, but if someone else would like to give it a shot, go for it. :)

What if I wanted to change all hyphens to em dashes? And better yet in a specified paragraph class?

Is this possible? How would you do that?

My money’s on the second (string-based) method as the best performing approach, but it would be helpful to provide benchmark results in your post so that each solution’s performance can be taken into account…

And I wonder what the best way would be of ensuring that if any of the three approaches are accidentally (or intentionally) run multiple times the changes are not reapplied each time, resulting in new lines of 3,4,5,etc words…?

  $('h2').each(function() {
    var h2Contents = $(this).html().split(" ");
    h2Contents[h2Contents.length-2] = '<span style="white-space: nowrap; color: red;">' + h2Contents[h2Contents.length-2];
    h2Contents[h2Contents.length-1] = h2Contents[h2Contents.length-1] + '</span>';
    $(this).html(h2Contents.join(' '));
  });