HTML..XHTML.The.Definitive.Guide..5th.Ed.1002002 [Electronic resources] نسخه متنی

7.2 Ordered Lists

Use an ordered list when the sequence of
the list items is important. A list of instructions is a good
example, as are tables of contents and lists of document footnotes or
endnotes.

7.2.1 The <ol> Tag

The typical
browser formats the contents of an ordered list just like an
unordered list, except that the items are numbered instead of
bulleted. The numbering starts at one and is incremented by one for
each successive ordered list element tagged with
<li>. [<li>]

HTML 3.2 introduced a number of features that provide a wide variety
of ordered lists. You can change the start value of the list and
select any of five different numbering styles.

Here is a sample XHTML ordered list:

<h3>Pickled Kumquats</h3>
Here's an easy way to make a delicious batch of pickled 'quats:
<ol>
<li>Rinse 50 pounds of fresh kumquats</li>
<li>Bring eight gallons white vinegar to rolling boil</li>
<li>Add kumquats gradually, keeping vinegar boiling</li>
<li>Boil for one hour, or until kumquats are tender</li>
<li>Place in sealed jars and enjoy!</li>
</ol>

Netscape renders the example as shown in Figure 7-2.

Figure 7-2. An ordered list

7.2.1.1 The start attribute

Normally,
browsers automatically number
ordered list items beginning with the Arabic numeral 1. The
start attribute for the
<ol> tag lets you change that beginning
value. To start numbering a list at 5, for example:

<ol start=5>
<li> This is item number 5.</li>
<li> This is number six!</li>
<li> And so forth...</li>
</ol>

7.2.1.2 The type attribute

By
default, browsers number ordered list
items with a sequence of Arabic numerals. Besides being able to start
the sequence at some number other than 1, you can use the
type attribute with the
<ol> tag to change the numbering style
itself. The attribute may have a value of A for
numbering with capital letters, a for numbering
with lowercase letters, I for capital Roman
numerals, i for lowercase Roman numerals, or
1 for common Arabic numerals. (See Table 7-1.)

The start and type attribute
extensions work in tandem. The start attribute
sets the starting value of the item integer counter at the beginning
of an ordered list. The type attribute sets the
actual numbering style. For example, the following ordered list
starts numbering items at 8, but because the style of numbering is
set to i, the first number is the lowercase Roman
numeral "viii." Subsequent items
are numbered with the same style, and each value is incremented by 1,
as shown in this HTML example, and rendered as shown in Figure 7-3:[1]

[1] Notice that we
don't include the </li> end
tag in the HTML example but do in all the XHTML ones. Some end tags
are optional with HTML but must be included in all XHTML
documents.

<ol start=8 type="i">
<li> This is the Roman number 8.
<li> The numerals increment by 1.
<li> And so forth...
</ol>

Figure 7-3. The start and type attributes work in tandem

The type and value of individual items in a list can be different
from those of the list as a whole, described in Section 7.3.1. As mentioned earlier, the
start and type attributes are
deprecated in HTML 4 and XHTML. Consider using style sheets instead.

7.2.1.3 Compact ordered lists

Like the <ul> tag, the
<ol> tag has an optional
compact
attribute that is deprecated in the HTML 4 and XHTML
standards. Unless you absolutely need to use it,
don't.

7.2.1.4 The class, dir, id, lang, event, style, and title attributes

These attributes are applicable with ordered lists, too; their
effects are identical to those for unordered lists.Section 7.1.1.3] [Section 7.1.1.4] [Section 7.1.1.5] [Section 7.1.1.6]