Wednesday, 14 December 2011

HTML Styles - CSS

CSS is used to style HTML elements.

Look! Styles and colors

This text is in Verdana and red

This text is in Times and blue

This text is 30 pixels high

Try it yourself

Styling HTML with CSS

CSS was introduced together with HTML 4, to provide a better way to style HTML elements.
CSS can be added to HTML in the following ways:

in Cascading Style Sheet files (CSS files)
in the <style> element in the HTML head section
in the style attribute in single HTML elements

Using the HTML Style Attribute

It is time consuming and not very practical to style HTML elements using the style attribute.
The preferred way to add CSS to HTML, is to put CSS syntax in separate CSS files.
However, in this HTML tutorial we will introduce you to CSS using the style attribute. This is done to simplify the examples. It also makes it easier for you to edit the code and try it yourself.
You can learn everything about CSS in our CSS Tutorial.

HTML Style Example - Background Color

The background-color property defines the background color for an element:

Example

<html>

<body style="background-color:yellow;">
<h2 style="background-color:red;">This is a heading</h2>
<p style="background-color:green;">This is a paragraph.</p>
</body>

</html>

Try it yourself »

The background-color property makes the "old" bgcolor attribute obsolete.
Try it yourself: Background color the old way

HTML Style Example - Font, Color and Size

The font-family, color, and font-size properties defines the font, color, and size of the text in an element:

Example

<html>

<body>
<h1 style="font-family:verdana;">A heading</h1>
<p style="font-family:arial;color:red;font-size:20px;">A paragraph.</p>
</body>

</html>

Try it yourself »

The font-family, color, and font-size properties make the old <font> tag obsolete.

HTML Style Example - Text Alignment

The text-align property specifies the horizontal alignment of text in an element:

Example

<html>

<body>
<h1 style="text-align:center;">Center-aligned heading</h1>
<p>This is a paragraph.</p>
</body>

</html>

Try it yourself »

The text-align property makes the old <center> tag obsolete.
Try it yourself: Centered heading the old way

Deprecated Tags and Attributes

In HTML 4, several tags and attributes were deprecated. Deprecated means that they will not be supported in future versions of HTML.
Remark

The message is clear: Avoid using deprecated tags and attributes!
These tags and attributes should be avoided:

Tags	Description
<center>	Deprecated. Defines centered content
<font> and <basefont>	Deprecated. Defines HTML fonts
<s> and <strike>	Deprecated. Defines strikethrough text
<u>	Deprecated. Defines underlined text
Attributes	Description
align	Deprecated. Defines the alignment of text
bgcolor	Deprecated. Defines the background color
color	Deprecated. Defines the text color

For all of the above: Use styles instead!

HTML Fonts

The HTML <font> Tag Should NOT be Used

The <font> tag is deprecated in HTML 4, and removed from HTML5.
The World Wide Web Consortium (W3C) has removed the <font> tag from its recommendations.
In HTML 4, style sheets (CSS) should be used to define the layout and display properties for many HTML elements.
The example below shows how the HTML could look by using the <font> tag:

Example

<p>
<font size="5" face="arial" color="red">
This paragraph is in Arial, size 5, and in red text color.
</font>
</p>

<p>
<font size="3" face="verdana" color="blue">
This paragraph is in Verdana, size 3, and in blue text color.
</font>
</p>

HTML Text Formatting

This text is bold

This text is big

This text is italic

This is computer output

This is_subscript and ^superscript

Try it yourself »

HTML Formatting Tags

HTML uses tags like <b> and <i> for formatting output, like bold or italic text.
These HTML tags are called formatting tags (look at the bottom of this page for a complete reference).

	Often <strong> renders as <b>, and <em> renders as <i>. However, there is a difference in the meaning of these tags: <b> or <i> defines bold or italic text only. <strong> or <em> means that you want the text to be rendered in a way that the user understands as "important". Today, all major browsers render strong as bold and em as italics. However, if a browser one day wants to make a text highlighted with the strong feature, it might be cursive for example and not bold!

Often <strong> renders as <b>, and <em> renders as <i>.

However, there is a difference in the meaning of these tags:

<b> or <i> defines bold or italic text only.

<strong> or <em> means that you want the text to be rendered in a way that the user understands as "important". Today, all major browsers render strong as bold and em as italics. However, if a browser one day wants to make a text highlighted with the strong feature, it might be cursive for example and not bold!

HTML Text Formatting Tags

Tag	Description
<b>	Defines bold text
<big>	Defines big text
<em>	Defines emphasized text
<i>	Defines italic text
<small>	Defines small text
<strong>	Defines strong text
<sub>	Defines subscripted text
<sup>	Defines superscripted text
<ins>	Defines inserted text
<del>	Defines deleted text

HTML "Computer Output" Tags

Tag	Description
<code>	Defines computer code text
<kbd>	Defines keyboard text
<samp>	Defines sample computer code
<tt>	Defines teletype text
<var>	Defines a variable
<pre>	Defines preformatted text

HTML Citations, Quotations, and Definition Tags

Tag	Description
<abbr>	Defines an abbreviation
<acronym>	Defines an acronym
<address>	Defines contact information for the author/owner of a document
<bdo>	Defines the text direction
<blockquote>	Defines a long quotation
<q>	Defines a short quotation
<cite>	Defines a citation
<dfn>	Defines a definition term

Tuesday, 13 December 2011

HTML VIDEO

Monday, 12 December 2011

HTML Paragraphs

Paragraphs are defined with the <p> tag.

Example

<p>This is a paragraph</p>
<p>This is another paragraph</p>

Try it yourself »

Note: Browsers automatically add an empty line before and after a paragraph.

Don't Forget the End Tag

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

Example

<p>This is a paragraph
<p>This is another paragraph

Try it yourself »

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.

HTML Line Breaks

Use the <br /> tag if you want a line break (a new line) without starting a new paragraph:

Example

<p>This is<br />a para<br />graph with line breaks</p>

Try it yourself »

The <br /> element is an empty HTML element. It has no end tag.

<br> or <br />

In XHTML, XML, elements with no end tag (closing tag) are not allowed.
Even if <br> works in all browsers, writing <br /> instead works better in XHTML and XML applications.

HTML Output - Useful Tips

You cannot be sure how HTML will be displayed. Large or small screens, and resized windows will create different results.
With HTML, you cannot change the output by adding extra spaces or extra lines in your HTML code.
The browser will remove extra spaces and extra lines when the page is displayed. Any number of lines count as one line, and any number of spaces count as one space.
Try it yourself
(The example demonstrates some HTML formatting problems)

HTML Tag Reference

W3Schools' tag reference contains additional information about HTML elements and their attributes.

Tag	Description
<p>	Defines a paragraph
<br />	Inserts a single line break

HTML Headings

Headings are defined with the <h1> to <h6> tags.
<h1> defines the most important heading. <h6> defines the least important heading.

Example

<h1>This is a heading</h1>
<h2>This is a heading</h2>
<h3>This is a heading</h3>

Try it yourself »

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 Lines

The <hr /> tag creates a horizontal line in an HTML page.

The hr element can be used to separate content:

Example

<p>This is a paragraph</p>
<hr />
<p>This is a paragraph</p>
<hr />
<p>This is a paragraph</p>

Try it yourself »

HTML Comments

Comments can be inserted into the HTML code to make it more readable and understandable. Comments are ignored by the browser and are not displayed.
Comments are written like this:

Example

Try it yourself »

Note: There is an exclamation point after the opening bracket, but not before the closing bracket.

HTML Tag Reference

W3Schools' tag reference contains additional information about these tags and their attributes.
You will learn more about HTML tags and attributes in the next chapters of this tutorial.

Tag	Description
<html>	Defines an HTML document
<body>	Defines the document's body
<h1> to <h6>	Defines HTML headings
<hr />	Defines a horizontal line
<!-->	Defines a comment

Saturday, 10 December 2011

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 <a> tag. The link address is specified in the href attribute:

Example

Try it yourself »

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.
Remark

Tip: 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 in our:
Complete HTML Reference
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)