jQuery get value of selected radio button

Question

The problem statement is simple. I need to see if user has selected a radio button from a radio group. Every radio button in the group share same id.

The problem is

Answer 1

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This will return, checked radio button value.

if($("input[type='radio'].radioBtnClass").is(':checked')) {
    var card_type = $("input[type='radio'].radioBtnClass:checked").val();
    alert(card_type);
}