HTML Headings, Lines and Comments

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>

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

<!– This is a comment –>

 

HTML Tip – How to View HTML Source

Have you ever seen a Web page and wondered “Hey! How did they do that?”

To find out, right-click in the page and select “View Source” (IE) or “View Page Source” (Firefox), or similar for other browsers. This will open a window containing the HTML code of the page.

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

<a href=”http://www.abc.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.

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

Below is a list of some attributes that can be used on any HTML element:

Attribute Description
class Specifies one or more classnames for an element (refers to a class in a style sheet)
id Specifies a unique id for an element
style Specifies an inline CSS style for an element
title Specifies extra information about an element (displayed as a tool tip)

Headings, Paragraphs, Links and Images

HTML Headings

HTML headings are defined with the <h1> to <h6> tags.
<h1>This is a heading</h1>
<h2>This is a heading</h2>
<h3>This is a heading</h3>

HTML paragraphs are defined with the <p> tag.
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>

HTML links are defined with the <a> tag.
<a href=”http://www.google.com”>This is a link</a>

HTML images are defined with the <img> tag.
<img src=”abc.jpg” width=”104″ height=”142″>

HTML documents are defined by HTML elements.


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>

* 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

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

<!DOCTYPE html>
<html><body>
<p>This is my first paragraph.</p>
</body></html>

The example above contains 3 HTML elements.

HTML Example Explained

The <p> element:

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

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

The <body> element:

<body>
<p>This is my first paragraph.</p>
</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 p element).

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 element).


Don’t Forget the End Tag

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

<p>This is a paragraph
<p>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.

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

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


HTML Tip: Use Lowercase Tags

HTML tags are not case sensitive: <P> means the same as <p>. Many web sites use uppercase HTML tags.

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