JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://jquery/jquery/dist/jquery.js"></script>
<select>
    <option value="1" selected="selected">One</option>
    <option value="2">Two</option>
</select>

<button onclick="javascript:alert($('input,select :selected').length)">
    test
</button>

JavaScript

var res;
try {
    console.log("qsa for 'input, select :selected' ");
    res = document.querySelectorAll("input, select :selected");
    console.log("No Throw");
    console.log(res.length);
} catch (qsaError) {
    console.log("Error");
    console.log(qsaError);
}

try {
    console.log("qsa for 'select :selected, input' ");
    res = document.querySelectorAll("select :selected, input");
    console.log("No Throw");
    console.log(res.length);
} catch (qsaError) {
    console.log("Error");
    console.log(qsaError);
}
try {
    console.log("qsa for 'select :selected' ");
    res = document.querySelectorAll("select :selected");
    console.log("No Throw");
    console.log(res.length);
} catch (qsaError) {
    console.log("Error");
    console.log(qsaError);
}