ol
elementli
elements.reversed
start
type
interface HTMLOListElement : HTMLElement { attribute boolean reversed; attribute long start; attribute DOMString type; };
The ol
element represents a list of items, where the items have been intentionally ordered, such that changing the order would change the meaning of the document.
The items of the list are the li
element child nodes of the ol
element, in tree order.
The reversed
attribute is a boolean attribute. If present, it indicates that the list is a descending list (..., 3, 2, 1). If the attribute is omitted, the list is an ascending list (1, 2, 3, ...).
The start
attribute, if present, must be a valid integer giving the ordinal value of the first list item.
The type
attribute can be used to specify the kind of marker to use in the list, in the cases where that matters (e.g. because items are to be referenced by their number/letter). The attribute, if specified, must have a value that is a case-sensitive match for one of the characters given in the first cell of one of the rows of the following table.
Keyword | State | Description | Examples for values 1-3 and 3999-4001 | |||||||
---|---|---|---|---|---|---|---|---|---|---|
1 (U+0031) |
decimal | Decimal numbers | 1. | 2. | 3. | ... | 3999. | 4000. | 4001. | ... |
a (U+0061) |
lower-alpha | Lowercase latin alphabet | a. | b. | c. | ... | ewu. | ewv. | eww. | ... |
A (U+0041) |
upper-alpha | Uppercase latin alphabet | A. | B. | C. | ... | EWU. | EWV. | EWW. | ... |
i (U+0069) |
lower-roman | Lowercase roman numerals | i. | ii. | iii. | ... | mmmcmxcix. | i̅v̅. | i̅v̅i. | ... |
I (U+0049) |
upper-roman | Uppercase roman numerals | I. | II. | III. | ... | MMMCMXCIX. | I̅V̅. | I̅V̅I. | ... |
The reversed
, start
, and type
IDL attributes must reflect the respective content attributes of the same name. The start
IDL attribute has the same default as its content attribute.
The following markup shows a list where the order matters, and where the ol
element is therefore appropriate. Compare this list to the equivalent list in the ul
section to see an example of the same items using the ul
element.
<p>I have lived in the following countries (given in the order of when I first lived there):</p> <ol> <li>Switzerland <li>United Kingdom <li>United States <li>Norway </ol>
Note how changing the order of the list changes the meaning of the document. In the following example, changing the relative order of the first two items has changed the birthplace of the author:
<p>I have lived in the following countries (given in the order of when I first lived there):</p> <ol> <li>United Kingdom <li>Switzerland <li>United States <li>Norway </ol>