title: Must a floated div containing an image have a width?
body: <p>I'm exploring responsive design and learning more about CSS and was delighted to discover that if I place an image inside a div and float it, I don't need to assign the div a width. Apparently, it automatically assumes the width of the enclosed image. (I should also point out that I've stripped the width and height attributes out of all my images.)</p>
  
  <p>I'm working on a Mac, and it works beautifully with Chrome, Safari, Firefox and Opera at various screen sizes. (Actually, I'm having a few problems with Firefox, but the floats are working fine.)</p>
  
  <p>However, some sources say you should always assign a width to a floated div. So, just to make sure I know what I'm getting into, can anyone give me some specific reasons I should assign widths to these divs? I assume defined widths might be required by some older browsers. Also, I haven't tested my pages in Internet Explorer yet.</p>