The "id" attribute assigns an identifier to the associated element. This identifier must be unique in the document and can be used to refer to that element.
Example:
Code begin
<p id="paragraph1">This is the first paragraph named as paragraph1. To dynamically change its properties use this identifier.</p>Code end
The "class" attribute assigns a class name (or a list of class names separated by spaces) to the container element. It's used with style sheets and tells the browser the class to which the element is associated with. A class gives visual attributes to elements.
Example:
Code begin
<p class="references">This article is based on the book "Wind in the trees" by Jhon L. Brooks</p>
<p class="references important">This article is based on the book "Wind in the trees" by Jhon L. Brooks... and is more important than the one before.</p>Code end
Defines a visual style of this element. Is a better practice to define styles attributes in external style sheets grouping them in classes. Attributes in the "style" parameter must preserve this order "name : value" and be separated by a semi-colon.
If you're writing XHTML code it's recommended not to use this attribute and try style sheet classes (with the "class" attribute).
Example:
Code begin
<p style="color: #0000FF; font-size: 12pt">This is a paragraph with a defined style</p> <p>And this is another text without style.</p>Code end
Indicates a title for the element. Used to give a short description about the element that is usually shown as a "tool tip" when the user put the mouse pointer over the element.
Specifies the language of an element's content. The default value in "unknown".
When writing XHTML code the syntax "xml:lang" represents a preferred alternative in XHTML 1.0 and a replacement in XHTML 1.1 (e.g., xml:lang="en").
Example:
Code begin
<p lang="en">This is a paragraph in english.</p> <p lang="es">Este es un párrafo en español.</p>Code end
dir
Specifies the text direction of the element's contents and attribute values, as well as tables directionality. It has two possible values that are case insensitive:
RTL: Right to left.
LTR: Left to right.
Example:
Code begin
<q lang="he" dir="rtl">...a Hebrew quotation...</q>Code end
Specifies the position of this element in the tabbing order. The tabbing order defines the sequence with all the elements than can receive the focus. Users can navigate this sequence via keyboard (usually with the "tab" key).
This attribute specifies the image map to which this element is related to. To work correctly the "usemap" attribute of this element must match the "name" attribute from the associated HTML map tag.
Example:
Code begin
<img src="http://www.htmlquick.com/img/examples/nav1.jpg" usemap="#nav1" alt="Navigation menu" /> Code end
Specifies the content type of the data defined in the "classid" attribute. This attribute lets the browser know if it supports the object before download it.
May be used to specify a space-separated list of URIs that provide relevant archives for the object. This may help improve the loading time by preloading the archives content.
declare
This boolean attribute decides if the object's definition is a declaration only. If so, other object definition may be set as an instance by referring to this declaration.
Remember that boolean attributes must be defined as attr_name="attr_name" to be XHTML code compliant.
