HTML Part 3

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

Tip: You will learn about attributes in the next chapter of this tutorial.

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Nested HTML Elements

Most HTML elements can be nested (can contain other HTML elements).

HTML documents consist of nested HTML elements.

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HTML Document Example

This is my first paragraph.

The example above contains 3 HTML elements.

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HTML Example Explained

The

element:

This is my first paragraph.

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 element:

This is my first paragraph.

The element defines the body of the HTML document.
The element has a start tag and an end tag .
The element content is another HTML element (a p element).

The element:

This is my first paragraph.

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

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Don't Forget the End Tag

Some HTML elements might display correctly even if you forget the end tag:

This is a paragraph

This is a paragraph

The example above works in most browsers, because the closing tag is considered optional.

Never rely on this. Many HTML elements will produce unexpected results and/or errors if you forget the end tag .

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Empty HTML Elements

HTML elements with no content are called empty elements.

is an empty element without a closing tag (the
tag defines a line break).

Tip: In XHTML, all elements must be closed. Adding a slash inside the start tag, like
, is the proper way of closing empty elements in XHTML (and XML).

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HTML Tip: Use Lowercase Tags

HTML tags are not case sensitive:

means the same as

. Many web sites use uppercase HTML tags.

W3Schools use lowercase tags because the World Wide Web Consortium (W3C) recommends lowercase in HTML 4, and demands lowercase tags in XHTML.

HTML Attributes

• HTML elements can have attributes
• Attributes provide additional information about an 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 tag. The link address is specified in the href attribute:

This is a link

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.

Tip: In some rare situations, when the attribute value itself contains quotes, it is necessary to use single quotes: name='John "ShotGun" Nelson'

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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.

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HTML Attributes Reference

A complete list of legal attributes for each HTML element is listed on last page of this document

Below is a list of some attributes that are standard for most HTML elements:

Attribute	Value	Description
class	classname	Specifies a classname for an element
id	id	Specifies a unique id for an element
style	style_definition	Specifies an inline style for an element
title	tooltip_text	Specifies extra information about an element (displayed as a tool tip)

HTML Headings

Headings are defined with the

to

tags.

defines the most important heading.

defines the least important heading.

This is a heading

This is a heading

This is a heading

Note: Browsers automatically add some empty space (a margin) before and after each heading.

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Headings Are Important

Use HTML headings for headings only. Don't use headings to make text BIG or bold.

Search engines use your headings to index the structure and content of your web pages.

Since users may skim your pages by its headings, it is important to use headings to show the document structure.

H1 headings should be used as main headings, followed by H2 headings, then the less important H3 headings, and so on.