Home >Web Front-end >HTML Tutorial >HTML commonly used tags optgroup, sub, sup and bdo sample code_HTML/Xhtml_web page production

HTML commonly used tags optgroup, sub, sup and bdo sample code_HTML/Xhtml_web page production

WBOYOriginal: 2016-05-16 16:42:111510browse

Optgroup is used in select tags to make the drop-down list content more organized

Copy code

The code is as follows:

sub superscript
sup subscript can be used together with for comments
dbo dir tag can be used together to change the output direction of text , right->left

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>Four uncommon HTML tags optgroup, sub, sup and bdo. </title> <style type="text/css"> fieldset{width:300px;padding:5px 5px; margin:30px auto; display:block; line-height:125%; font-size:15px;} legend{margin-left:15px; font-size:18px; color:red; } bdo{color:red;} </style> </head> <body> <fieldset><legend>optgroup</legend> <select> <optgroup label="HTML tag"> <option>table</option> <option>tr</option> <option>td</option> <option>th</option> </optgroup> <optgroup label="ASP built-in objects"> <option>cookies</option> <option>session</option> <option>application</option> <option>redirect</option> </optgroup> </select> <select> <optgroup label=""> <option>....</option> </optgroup> </select> </fieldset> <fieldset class="sub"> <legend>sub tag</legend> X<sub>2</sub> Superscript X<sub>2</sub> X<sup>2</sup> subscript X<sup>2</sup> <hr /> Combined with the <em> tag, it can be used for comments, for example: flying<sub><em>Note: HTML XHTML web page encoding Moderator</em></sub> </fieldset> <fieldset><legend>bdo tag</legend> <bdo dir="ltr">I love you very much</bdo> <bdo dir="rtl">You love me so much</bdo> The output result is <bdo dir="ltr">I love you very much</bdo> <bdo dir="rtl">You love me so much</bdo> Note: When using the bod tag, you must use the dir tag attribute. ltr refers to the arrangement order from left to right, and rtl refers to the arrangement order from right to left. </p> </p> </fieldset> </body> </html>

Tip: You can modify part of the code before running

Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Previous article：Detailed explanation of the TARGET attribute of html hyperlink tag A_HTML/Xhtml_Web page productionNext article：Detailed explanation of the TARGET attribute of html hyperlink tag A_HTML/Xhtml_Web page production

See more

Summary of Html knowledge
How to learn HTML quickly
The difference between html xhtml xml
The difference between src and href attributes
About HTML5 and CSS replacement use

HTML commonly used tags optgroup, sub, sup and bdo sample code_HTML/Xhtml_web page production

Related articles