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HTML tags optgroup and sub and sup and bdo sample code

黄舟
黄舟Original
2017-07-03 09:34:111385browse

HTML tagThe usage and sample code of optgroup, sub, sup and bdo, friends in need can refer to it. optgroup is used in the select tag to make the drop-down list content more organized

<select>
<optgroup label="aaa">
<option>分清是非</option>
<option>分清是非</option>
<option>分清是非</option>
</optgroup>
<optgroup style="color:#C30" label="bbb">
<option>分清是非</option>
<option>分清是非</option>
<option>分清<br/>是非</option>
</optgroup>
</select>


sub superscript
sup subscript can be used with 12616b79038dde837c4317a6386161ccleft

<!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>4个不常用HTML标签optgroup、sub、sup和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标记">
<option>table</option>
<option>tr</option>
<option>td</option>
<option>th</option>
</optgroup>
<optgroup label="ASP内置对象">
<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标记</legend>
X<sub>2</sub> 上标 X<sub>2</sub>
X<sup>2</sup> 下标 X<sup>2</sup>
<hr />
与<em>标签结合可以用于注释,例:
flying<sub><em>注:HTML XHTML网页编码 版主</em></sub>
</fieldset>
<fieldset><legend>bdo标记</legend>
<bdo dir="ltr">我非常爱你</bdo>
<bdo dir="rtl">你爱常非我</bdo>
输出结果为  
<bdo dir="ltr">我非常爱你</bdo>
<bdo dir="rtl">你爱常非我</bdo>
注:使用bod标签时必须连用dir标签属性,ltr指从左到右的编排顺序,rtl指从右到左的编排顺序。
</p>
</p>
</fieldset>
</body>
</html>

Tip: You can modify part of the code before running it

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