Part 2 - Elements & Attributes of HTML

HTML Elements

An HTML element is everything from the start tag to the end tag:

Start tag *	Element content	End tag *
<p>	This is a paragraph	</p>
<a href="/default.htm" >	This is a link	</a>
<br />

* The start tag is often called the opening tag. The end tag is often called the closing tag.

HTML Element Syntax

An HTML element starts with a start tag / opening tag
An HTML element ends with an end tag / closing tag
The element content is everything between the start and the end tag
Some HTML elements have empty content
Empty elements are closed in the start tag
Most HTML elements can have attributes

(You will learn about element attributes in the next chapter of this tutorial)

Nested HTML Elements

Most HTML elements can be nested (can contain other HTML elements).
HTML documents consist of nested HTML elements.

HTML Document Example

<html>

<body>

<p>This is my first paragraph</p>

</body>
</html>

The example above contains 3 HTML elements.

Example Explained

The element:

<p>This is my first paragraph</p>

The element defines a paragraph in the HTML document
The element has a start tag and an end tag 
The element content is: This is my first paragraph

The <body> element:

<body>

This is my first paragraph
</body>

The <body> element defines the body of the HTML document
The element has a start tag <body> and an end tag </body>
The element content is another HTML element (a paragraph)

The <html> element:

<html>

<body>

<p>This is my first paragraph</p>

</body>

</html>

The <html> element defines the whole HTML document.
The element has a start tag <html> and an end tag </html>
The element content is another HTML element (the body)

Don't Forget the End Tag

Most browsers will display HTML correctly even if you forget the end tag:

<p>This is a paragraph

<p>This is a paragraph

The example above will work in most browsers, but don't rely on it. Forgetting the end tag can produce unexpected results or errors.
Note: Future version of HTML will not allow you to skip end tags.

Empty HTML Elements

HTML elements without content are called empty elements. Empty elements can be closed in the start tag.
 is an empty element without a closing tag (it defines a line break).
In XHTML, XML, and future versions of HTML, all elements must be closed.
Adding a slash to the start tag, like , is the proper way of closing empty elements, accepted by HTML, XHTML and XML.
Even if works in all browsers, writing instead is more future proof.

HTML Tip: Use Lowercase Tags

HTML tags are not case sensitive: means the same as . Plenty of web sites use uppercase HTML tags in their pages.
W3Schools use lowercase tags because the World Wide Web Consortium (W3C) recommends lowercase in HTML 4, and demands lowercase tags in future versions of (X)HTML.

HTML Attributes

HTML elements can have attributes
Attributes provide additional information about the element
Attributes are always specified in the start tag
Attributes come in name/value pairs like: name="value"

Attribute Example

HTML links are defined with the <a> tag. The link address is provided as an attribute:

<a href="http://www.YourSite.com">This is a link</a>

Always Quote Attribute Values

Attribute values should always be enclosed in quotes.
Double style quotes are the most common, but single style quotes are also allowed.
In some rare situations, like when the attribute value itself contains quotes, it is necessary to use single quotes:
name='John "ShotGun" Nelson'

HTML Tip: Use Lowercase Attributes

Attribute names and attribute values are case-insensitive.
However, the World Wide Web Consortium (W3C) recommends lowercase attributes/attribute values in their HTML 4 recommendation
Newer versions of (X)HTML will demand lowercase attributes.

HTML Attributes Reference

A full list of legal attributes for each HTML element is listed in our:
Complete HTML Reference
Below is a list of some attributes that are standard for most HTML elements:

Attribute	Value	Description
class	class_rule or style_rule	The class of the element
id	id_name	A unique id for the element
style	style_definition	An inline style definition
title	tooltip_text	A text to display in a tool tip

For more information about standard attributes:
HTML Standard Attributes Reference

E-Learning

Saturday, 30 July 2011