Radio Button Check W/ Jquery

What would be the best way to loop through all radio buttons on my page and alert the user if one of them is unchecked for a particular question? Note: there are multiple questions

Solution 1:

if (undefined === $("input[name='answer8']:checked").val()) {
    // do something
}

Solution 2:

Try these:

Find all radio groups which haven't been selectedValidation of radio button group using jQuery validation plugin