> Here's a general question about CSS that I've been able to quite figure out. > If one has a DIV that will only appear once per page, which should one use: > a class or an id? > Classes are obviously useful at applying to multiple elements, or applying > multiple classes to one element. What advantages have that classes do not? > Specificity comes to mind, but the CSS rules regarding this are hazy in my > mind and I do not know if ids provide more specificity than classes.
If the element is only available once on the page that either means it is a special case or it is an important element of the overall site layout. This warrants an ID rather than a class, for several reasons: 1) A designer who will look at your CSS and XHTML and needs to maintain it realises immediately that this element can be there once and is something unique 2) The specificity is higher than a div with a class 3) It is shorter to write child selectors: #foo p a vs. div.foo p a (yes you could argue that div#foo would be needed, but the higher specificity of an ID warrants the ommission) 4) Scripts could reach your DIV via getElementById rather than using an extra method and looping to find the DIV with the className Classes on the other hand give a CSS-savvy user the information that the element is part of a collection and can appear several times. -- Chris Heilmann Blog: http://www.wait-till-i.com Writing: http://icant.co.uk/ Binaries: http://www.onlinetools.org/ ______________________________________________________________________ css-discuss [EMAIL PROTECTED] http://www.css-discuss.org/mailman/listinfo/css-d List wiki/FAQ -- http://css-discuss.incutio.com/ Supported by evolt.org -- http://www.evolt.org/help_support_evolt/
