Contar grupos de radios

by Luiz Silva

HTML

<input type="radio" name="group[001]" id="1">apple
<input type="radio" name="group[001]" id="2">pineapple
<input type="radio" name="group[001]" id="3">melon
    <hr/>
<input type="radio" name="group[002]" id="4">strawberry
<input type="radio" name="group[002]" id="5">orange
<input type="radio" name="group[002]" id="6">kiwi
    <hr/>
<input type="radio" name="group[003]" id="4">a
<input type="radio" name="group[003]" id="5">b
<input type="radio" name="group[003]" id="6">c
    <hr/>
<input type="radio" name="group[004]" id="4">x
<input type="radio" name="group[004]" id="5">y
<input type="radio" name="group[004]" id="6">z
    <hr/>
<input type="radio" name="group[005]" id="4">a
<input type="radio" name="group[005]" id="5">s
<input type="radio" name="group[005]" id="6">d
    <hr/>
    <button disabled>Botão</button>
    <div></div>

JavaScript

$('input').change(function() {
    
    //habilita/desabilita botão
    $('button').prop('disabled', 
           $('input[type="radio"]:checked').length < 5);
    
});