Dreamweaver - CSS question IDs and Class

Author

CSS question IDs and Class

Anthony LeBaron

2005-03-08, 6:40 pm

Slogging through CSS and slowly making the transition away from tables.

Understand the diff between IDs (#style) which are unique to an element, and
Class (.style) which can be used on multiple elements. But I can't
understand why you would choose to use the ID tag, when it would be just as
simple to use a class and use it only once.

Is this a dumb question? I dunno.

Michael Fesser

2005-03-08, 6:41 pm

.oO(Anthony LeBaron)

>Slogging through CSS and slowly making the transition away from tables.
>
>Understand the diff between IDs (#style) which are unique to an element, and
>Class (.style) which can be used on multiple elements. But I can't
>understand why you would choose to use the ID tag, when it would be just as
>simple to use a class and use it only once.

There's much more about IDs. They identify an element, so that this
element can be accessed directly and manipulated with client-side
scripting (DOM, document object model).

Additionally ID selectors are more specific than anything else, which
becomes an issue when more than one selector apply to an element
(cascading rules), e.g.

#foo {color: red}
..foo {color: blue}

<p id='foo' class='foo'>...</p>

Both selectors apply to the paragraph, what will be its color? It will
be red, because #foo is more specific than .foo and will override it.

Micha

John Waller

2005-03-08, 6:45 pm

A brief overview:

http://www.mako4css.com/BasClass.htm

When should I use a class and when should I use an ID?
http://css-discuss.incutio.com/?page=ClassesVsIds

--
Regards

John Waller