February 2006
Intermediate to advanced
826 pages
63h 42m
English
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Attributes
An attribute clarifies or modifies an element’s actions. Attributes are indicated by attribute name and value pairs added to the start tag of the element (end tags never contain attributes). Attribute names and their accepted values are declared in the DTD; in other words, you cannot make up your own. You can add multiple attributes within a single opening tag. Attributes, if any, go after the tag name, each separated by one or more spaces. Their order of appearance is not important.
The syntax for an element with attributes is as follows:
<element attribute="value">content</element>
The following are examples of elements that contain attributes:
<head profile="http://gmpg.org/xfn/11">...</head> <img src="graphics/pixie.gif" alt="pixie" /> <table summary="This is a conference schedule.">...</table>
Most browsers cannot handle attribute values more than 1,024 characters in length. Values may be case-sensitive, particularly filenames or URLs.
XHTML requires that all attribute values be enclosed in quotation marks. Single or double quotation marks may be used, as long as they are used consistently throughout the document.
In HTML 4.01 and earlier, some values are permitted to go unquoted; for instance, if the value is a single word containing only letters (a-z or A-Z), digits (0-9), hyphens (-), periods (.), underscores (_), and colons (:). It is the best practice to quote all values, regardless of the Recommendation you are following.
Warning
Be careful not to leave out the closing ...