CSS Id and Class
The id and class Selectors
In addition to setting a style for a HTML element, CSS allows you to specify
your own selectors called "id" and "class".
The id Selector
The id selector is used to specify a style for a single, unique element.
The id selector uses the id attribute of the HTML element, and is defined
with a "#".
The style rule below will be applied to the element with id="para1":
Example
| #para1
{
text-align:center;
color:red;
}
------------------------------
SOME EXAMPLE CODE
<html>
<head>
<style type="text/css">
#para1
{
text-align:center;
color:red;
}
</style>
</head>
<body>
<p id="para1">Hello World!</p>
<p>This paragraph is not affected by the style.</p>
</body>
</html>
|
View it » |
 Do NOT start an ID name with a number! It will not work in Mozilla/Firefox.
The class Selector
The class selector is used to specify a style for a group of elements. Unlike the id
selector, the class selector is most often used on several elements.
This allows you to set a particular style for any HTML elements with the same class.
The class selector uses the HTML class
attribute, and is defined with a "."
In the example
below, all HTML elements with class="center" will be center-aligned:
Example
| .center {text-align:center;} |
View it » |
You can also specify that only specific HTML elements should be affected by a
class.
In the example
below, all p elements with class="center" will be center-aligned:
Example
| p.center {text-align:center;} |
View it » |
Do NOT start a class name with a number! This is only supported in Internet Explorer.
| 
