Adding validations to see if radio button is not selected

Question

I have the following code:

 
1. question 1

     Strongly         


        

Answer 1

Something like this?

if ($('input[type=radio]:checked').length <= 0) {
    alert("No radio checked")
}

Or do it by name?

if ($('input[name=question1]:checked').length <= 0) {
    alert("No radio checked")
}