Editing Radio button

{{short description|Graphical user interface control element}}
{{redirect|Option button|the key in Apple keyboards|Option key}}
{{more citations needed|date=November 2022}}
[[File:Option-buttons2.gif|thumb|Four options on a radio button. When a new option is chosen, the previously chosen option is unselected.]]
A '''radio button''' or '''option button'''<ref>{{Cite web |title=About Option Buttons |url=https://docs.oracle.com/cd/E14004_01/books/Fundamentals/fund_aboutrecordsfields006.htm |access-date=2025-02-02 |website=docs.oracle.com}}</ref> is a graphical control element that allows the user to choose only one of a predefined set of mutually exclusive options.<ref name="micro"/> The singular property of a radio button makes it distinct from [[checkbox]]es, where the user can select and unselect any number of items.

Radio buttons are arranged in groups of two or more and displayed on screen as, for example, a list of circular holes that can contain white space (for unselected) or a dot (for selected). Each radio button is normally accompanied by a label describing the choice that the radio button represents. The choices are mutually exclusive; when the user selects a radio button, any previously selected radio button in the same group becomes deselected (making it so only one can be selected). Selecting a radio button is done by clicking the mouse on (or touching the screen over) the button, or the caption, or by using a keyboard shortcut.

== Etymology ==
[[File:Car Radio of Analog Era.jpg|thumb|A radio with a row of five pop-out buttons]]
Radio buttons are named after the physical buttons that were used on old [[Radio_receiver#Broadcast_radio_receivers|radio]]s to select preset stations.<ref name="jit">{{cite web|last1=Yumashev|first1=Alex|title=The history of a radio-button|url=https://www.jitbit.com/alexblog/242-the-history-of-a-radio-button/|website=JitBit Founders Blog|access-date=14 September 2016}}</ref><ref name="micro">{{cite web|title=Radio Buttons|url=https://msdn.microsoft.com/en-us/library/windows/desktop/dn742436(v=vs.85).aspx|website=Windows Dev Center|access-date=14 September 2016}}</ref> When one of the buttons is pressed, the other buttons pop out while leaving the pressed one pushed in.

==HTML==
In [[form (web)|web forms]], the [[HTML element]] {{code|lang=html|code=<input type="radio">}} is used to display a radio button. Example:
<syntaxhighlight lang="html">
<form>
    <input type="radio" name="season" value="winter" id="winter" checked>
    <label for="winter">Winter</label>
    <input type="radio" name="season" value="spring" id="spring">
    <label for="spring">Spring</label>
    <input type="radio" name="season" value="summer" id="summer">
    <label for="summer">Summer</label>
    <input type="radio" name="season" value="autumn" id="autumn">
    <label for="autumn">Autumn</label>
</form>
</syntaxhighlight>A group of attributes is defined by name. In one group, only one radio button can be chosen.

==Unicode==
Version 6 of the [[Unicode]] standard includes a character designated to represent a radio button, (🔘) at code point 128,280 (U+1F518), found in the [https://www.unicode.org/charts/PDF/U1F300.pdf Miscellaneous Symbols and Pictographs] section. Similar characters are the [[mathematical operator]] {{unichar|2299|circled dot operator}} as well as {{unichar|25c9|fisheye}} and {{unichar|25CE|bullseye}}.

The font [[Wingdings]] 2 contains at position 153 and 158 [[glyph]]s that look like radio buttons.

== See also ==
* [[Checkbox]]

==References==
{{Reflist}}

==External links==
*{{IETF RFC|1866}}: the HTML 2.0 specification, which defined radio buttons on the web.
*[http://www.w3.org/TR/html401/interact/forms.html#radio W3 HTML 4.01 Specification]
*Usage of radio buttons in [http://java.sun.com/docs/books/tutorial/uiswing/components/button.html#radiobutton Sun's Java Programming Tutorial]
*{{cite web |url=http://www.useit.com/alertbox/20040927.html |title=Checkboxes vs. Radio Buttons |last=Nielsen |first=Jakob |author-link=Jakob Nielsen (usability consultant) |date=September 27, 2004 |website=[[Nielsen Norman Group]] |location=[Fremont, California] |type=article |access-date=November 12, 2014}}

{{Graphical control elements}}

[[Category:Graphical control elements]]