Senin, 30 April 2012

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.


Nested HTML Elements

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

HTML documents consist of nested HTML elements.


HTML Document Example




This is my first paragraph.




The example above contains 3 HTML elements.


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).


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 .


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).


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:

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.

RemarkTip: In some rare situations, 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 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.


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.

HTML part 2

What You Need

You don't need any tools to learn HTML at W3Schools.

  • You don't need an HTML editor
  • You don't need a web server
  • You don't need a web site

Editing HTML

HTML can be written and edited using many different editors like Dreamweaver and Visual Studio.

However, in this tutorial we use a plain text editor (like Notepad) to edit HTML. We believe using a plain text editor is the best way to learn HTML.

Use Your Test Web For Learning

We suggest you experiment with everything you learn at W3Schools by editing your web files with a text editor (like Notepad).

Note: If your test web contains HTML markup tags you have not learned, don't panic. You will learn all about it in the next chapters.


.HTM or .HTML File Extension?

When you save an HTML file, you can use either the .htm or the .html file extension. There is no difference, it is entirely up to you.

 
                  

HTML Headings

HTML headings are defined with the

to

tags.

This is a heading


This is a heading


This is a heading

HTML Paragraphs

HTML paragraphs are defined with the

tag.

This is a paragraph.


This is another paragraph.

HTML Links

HTML links are defined with the tag

HTML Images

HTML images are defined with the tag.


HTML Elements

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

Start tag *

Element content

End tag *

This is a paragraph

This is a link


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

HTML part 1

What is HTML?

HTML is a language for describing web pages.

  • HTML stands for Hyper Text Markup Language
  • HTML is not a programming language, it is a markup language
  • A markup language is a set of markup tags
  • HTML uses markup tags to describe web pages

HTML Tags

HTML markup tags are usually called HTML tags

  • HTML tags are keywords surrounded by angle brackets like
  • HTML tags normally come in pairs like and
  • The first tag in a pair is the start tag, the second tag is the end tag
  • Start and end tags are also called opening tags and closing tags

HTML Documents = Web Pages

  • HTML documents describe web pages
  • HTML documents contain HTML tags and plain text
  • HTML documents are also called web pages

The purpose of a web browser (like Internet Explorer or Firefox) is to read HTML documents and display them as web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page:

Example 1.1 :

<html>
  <head>
    <title>Hello HTML</title>
  </head>
  <body>
    <p>Hello World!</p>
  </body>
</html>