:checked - selector

by redky

HTML

<input name="a" type="radio">
<input name="a" type="radio" checked>
    
<input type="checkbox" name="c">
<input type="checkbox" name="c" checked>
    
<select name="" id="">
    <option value="a">a</option>
    <option value="b" selected>b</option>
</select>

JavaScript

var l = document.querySelectorAll( ':checked' );
alert( l.length );