In JavaScript, how can I get all radio buttons in the page with a given name?

Question

Like the title says, what's the best way in JavaScript to get all radio buttons on a page with a given name? Ultimately I will use this to determine which specific radio button is selected, so another way to phrase the question:

Given a string variable in JavaScript, how can I tell which exact radio button input element (if any) with that string as it's name is currently selected?

I'm not using jQuery. If you want to provide a jQuery answer, go ahead. Someone else might find it useful. But it won't help me and I won't upvote it.

Answer 1

You can use document.getElementsByName(), passing the name of the radio group, then loop over them inspecting the checked attribute, e.g. something like:

function getCheckedValue( groupName ) {
    var radios = document.getElementsByName( groupName );
    for( i = 0; i < radios.length; i++ ) {
        if( radios[i].checked ) {
            return radios[i].value;
        }
    }
    return null;
}

Answer 2

getElementsByName didn't work for me. I did this:

    var radios = document.getElementsByTagName('input');
    for (i = 0; i < radios.length; i++) {
        if (radios[i].type == 'radio' && radios[i].checked) {
            nbchecked++;
        }
    }