jquery/javascript select option randomly

Question

I want to select an option from select randomly.

<select class=".sel" id="sel">
    <option>a</option>
    <option>b</option>
    <option>c</option>
    <option>d</option>
</select>

actually i am using jQuery autocomplete.

Well,the question is how can i select option randomly from a select box ?

and what i tried is

function change_something(opt)
    {
    var randomOption=Math.floor(Math.random()*$(opt+' option').size());
    $(opt+ option["value='"+randomOption+"'"]).attr('selected', 'selected');
  }

Actually i am not a jQuery expert,so i am getting failed to change something .

@elclanrs Thank ou for the contribution to the question,i tried something ` var randomOption=Math.floor(Math.random()*$(opt+' option').size()); $(opt+ option["value='"+randomOption+"'"]).attr('selected', 'selected');` — Red
– Red, Commented Mar 6, 2012 at 4:10
how about looking at this first: stackoverflow.com/questions/7577047/… — Sudhir Bastakoti
– Sudhir Bastakoti, Commented Mar 6, 2012 at 4:14

elclanrs · Accepted Answer · 2012-03-06 04:16:34Z

11

Something like this should work:

var $options = $('#sel').find('option'),
    random = ~~(Math.random() * $options.length);

$options.eq(random).prop('selected', true);

http://jsfiddle.net/elclanrs/8DPMN/

answered Mar 6, 2012 at 4:16

elclanrs

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Comments

Daniil Ryzhkov · Accepted Answer · 2012-03-06 04:15:29Z

6

That's what you need

options = $("#sel > option")
options[Math.floor(Math.random() * options.length)].selected = true

Also, use class="sel" instead of class=".sel"

answered Mar 6, 2012 at 4:15

Daniil Ryzhkov

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3 Comments

jfriend00 Over a year ago

Did you try this? It doesn't seem to work for me in Chrome. It only works for me if I set xxx.selected = "selected".

Red Over a year ago

@jfriend00 i changed .sel to sel :D

user1106925 Over a year ago

@jfriend00: Are you setting the attribute? The property should be boolean as shown.

Ryan Kempt · Accepted Answer · 2012-03-06 04:12:18Z

3

This will work with your HTML example snippet.

var options = $("#sel > option");

var random = Math.floor(options.length * (Math.random() % 1));

$("#sel > option").attr('selected',false).eq(random).attr('selected',true);

answered Mar 6, 2012 at 4:12

Ryan Kempt

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1 Comment

Andres SK Over a year ago

what if i want to select one of those options randomly except the first option? (usually empty option) – andufo just now edit

Sudhir Bastakoti · Accepted Answer · 2012-03-06 04:23:12Z

-1

Change your class from ".sel" to "sel", then Try:


$(document).ready(function() {
   var index = Math.floor(Math.random() * $(".sel option").length) + 1;
  $("select option:nth-child(" + index + ")").prop("selected", true);
});

answered Mar 6, 2012 at 4:23

Sudhir Bastakoti

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