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

Question

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 = $(\         


        

Answer 1

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'));