Get the most selected radio input with Javascript

Question

I’m putting together a test, I just have the html structure done, I wanted to know how to know which of the radio input is most selected. Ex.: Most selected was "A)" then when submitting the form, is displaying the image corresponding to most letter "A)" and so on with the other alternatives "B)", "C"), "D)" E "E)"... is a very simple html...

1) Questão 1
</font><font size=4 color="black" face="arial"><p>
<label>
<input type="radio" name="questao1" value="a" /> A) resoposta 1 </label>
<br />
<label>
<input type="radio" name="questao1" value="b" /> B) resposta 2</label>
<br />
<label>
<input type="radio" name="questao1" value="c" /> C) resposta 3</label>
<br />
<label>
<input type="radio" name="questao1" value="d" /> D) resposta 4</label>
<br>
2) Questão 2
</font><font size=4 color="black" face="arial"><p>
<label>
<input type="radio" name="questao2" value="a" /> A) resoposta 1 </label>
<br />
<label>
<input type="radio" name="questao2" value="b" /> B) resposta 2</label>
<br />
<label>
<input type="radio" name="questao2" value="c" /> C) resposta 3</label>
<br />
<label>
<input type="radio" name="questao2" value="d" /> D) resposta 4</label>

Answer 1

You can do it this way:

var inputs = document.querySelectorAll('input');
var button = document.querySelector('button');
button.addEventListener('click', verificar);

function verificar() {
    var resultados = {};
    [].forEach.call(inputs, function (input) {
        var letra = input.value;
        if (!resultados[letra]) resultados[letra] = 0;
        if (input.checked) resultados[letra]++;
    });
    alert(JSON.stringify(resultados, null, 4));
}

jsFiddle: http://jsfiddle.net/yLgrtaw3/

I added a button to your HTML to start the check. So when the button is clicked, the function is called verificar going through all the inputs and filling the object resultados. Each time you find one that is checked (ie: input.checked) then he adds one more.

At the end I gave an Alert, but you could also do return function and use other logic that you have.