HTML <optgroup> tag

Function:

The HTML <optgroup> tag is used for grouping related options within your select list. This makes it easier for users to comprehend their choices when looking at a large list.

Difference between HTML and XHTML:

NONE

Example:

<select>
<optgroup label="India">
  <option value ="mumbai">Mumbai</option>
  <option value ="delhi">Delhi</option>
</optgroup>
<optgroup label="USA">
  <option value ="maryland">Marland</option>
  <option value ="newyork">New York</option>
</optgroup>
</select>

This will produce following result:

Online Practice:

To Become more comfortable - Do Online Practice

Attributes:

Attribute	Value	Description
disabled	disabled	Disables the input control. The button won't accept changes from the user. It also cannot receive focus and will be skipped when tabbing.
label	text	Defines a label to use when using <optgroup>.

Standard Attributes:

Attribute	Description
class	Document wide identifier
dir	Specifies the direction of the text
id	Document wide identifier
title	Specifies a title to associate with the element.
style	Helps to include inline casecadubf style sheet.
lang	Sets the language code.
xml:lang	Sets the language code.
tabindex	Helps determine the tabbing order

Event Attributes:

Attribute	Description
onclick	Script runs when a mouse click
ondblclick	Script runs when a mouse double-click
onmousedown	Script runs when mouse button is pressed
onmouseup	Script runs when mouse button is released
onmouseover	Script runs when mouse pointer moves over an element
onmousemove	Script runs when mouse pointer moves
onmouseout	Script runs when mouse pointer moves out of an element
onkeypress	Script runs when key is pressed and released
onkeydown	Script runs when key is pressed
onkeyup	Script runs when key is released