Find the value of radio button checked in jquery

I have this table containing 3 radio buttons, I want to find out whether a particular radio button is check or not at given point of time.

<table align="center" width="100%" border="0">
    <tbody>
        <tr>
            <td>
                <input type="ra开发者_如何学JAVAdio" name="compareRadio" value="all" checked="checked"/>
                <label>View All Records</label>
            </td>
            <td>
                <input type="radio" name="compareRadio" value="diff" />
                <label>View Differences</label>
            </td>
            <td>
                <input type="radio" name="compareRadio" id="patch" value="patches" />
                <label>Compare Patches</label>
            </td>
            <td>
                <input type="button" class="btn" value="Export Into Excel"/>
            </td>
        </tr>
    </tbody>
</table>

I send a request to the server, when the result comes back I want to identify whether patches radio button is selected or not.

So I did something like this.. but it returns all radio button

$.post("/csm/compare.action",
  { 
    sessiontoken: sessiontoken,
    compareCategory: "system",
    compareSubCategory:"patch",
    xml1:absP[0],
    xml2:absP[1]},
      function(resdata)
      {
        comparePatchData=resdata;
        comparePatchLoading=false;
        if($("input:radio[name=compareRadio]").val()=="patches")
        {
            //Trigger click on radio button for "same" campare
            $('input[name=compareRadio]:eq(2)').click();  //so that it refreshes the content
            $("input[name=compareRadio]:eq(2)").attr("checked", true);
            $('input[type="radio"]').removeAttr('disabled');
        }
      }
);

If you just want to know if it is checked or not, then you could do this:

if($('#patch:checked').length)
    // It is checked.

Or:

if($('input[value=patches]:checked').length)
    // It is checked.

The $() function returns an array of matched elements so you can check its length property to see how many things (if any) were matched.

References:

• :checked selector
• Attribute equals selector

To find out if particular checkbox is checked you can use jQuery's is():

if($('input[value=all]').is(':checked'))
{
   //Yep, it's checked
}