AspNyc AspNyc - 10 months ago 101
jQuery Question

jQuery: how to get the index of a checked radio button

I recently came across a StackOverflow answer that gave excellent instructions on how to get the value of a checked radio button using jQuery:

var radioVal = $("#myFormID input:radio[name='radioFieldName']:checked").val();
alert('Selected radio button value = ' + radioVal);

Now I'm trying to find the zero-based index of the checked radio button. I thought it would be relatively simple:

var radioIdx = $("#myFormID input:radio[name='radioFieldName']:checked").index();

is always returning a value of
. Any ideas on what I might be doing wrong?

Answer Source

This should work. You could do it all in one line but I broke it up to make it easier to read:

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");
var selectedIndex = radioButtons.index(radioButtons.find(':checked'));

EDIT: Verify that your selector is correct. Break it down step by step:

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");

// this should contain the count of all your radio buttons
var totalFound = radioButtons.length;

// this should contain the checked one
var checkedRadioButton = radioButtons.find(':checked');

// this should get the index of the found radio button based on the list of all
var selectedIndex = radioButtons.index(checkedRadioButton);

Which step is not producing the expected value in these?

EDIT: To show final solution

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");
var selectedIndex = radioButtons.index(radioButtons.filter(':checked'));