Enter HTML5 entry to proficient:<optgroup> label

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<optgroup> Label

Definitions and usage

<optgroup> label Definition option group. This element allows you to combine options. When you use a long list of options, combine the related options

Makes processing easier.

Differences between HTML 4.01 and HTML 5

No.

Example

<select>
<optgroup label= "Swedish Cars" >
<option http://www.aliyun.com/zixun/aggregation/9541.html ">value =" Volvo ">Volvo</option>
<option value = "Saab" >Saab</option>
</optgroup>
<optgroup label= "German Cars" >
<option value = "Mercedes" >Mercedes</option>
<option value = "Audi" >Audi</option>
</optgroup>
</select>

Property

The

Standard properties

Class, Contenteditable, ContextMenu, dir, draggable, id, irrelevant, lang, ref, Registrationmark, TabIndex, template, For a complete description of the title, visit the standard properties in HTML 5.

Event Properties

Onabort, onbeforeunload, onblur, onchange, onclick, OnContextMenu, ondblclick, Ondrag, Ondragend, OnDragEnter, OnDragLeave, OnDragOver, ondragstart, OnDrop, OnError, onfocus, onkeydown, onkeypress, onkeyup, onload, OnMessage, OnMouseDown, OnMouseMove, onmouseover, onmouseout, onmouseup, OnMouseWheel, OnResize, Onscroll, Onselect, onsubmit, OnUnload for a complete description, visit the event properties in HTML 5.