Toggling Radio Buttons with jQuery

Question

I am trying to toggle a couple of radio buttons using jQuery. But it is turning out to be not so simple.

<button id="toggler">click me</button><br>
<input type="radio" name="speeds" value="fast" checked>fast<br>
<input type="radio" name="speeds" value="slow">slow<br>

$('#toggler').click(function() {
    $('input[name="speeds"]').each(function(){
        $(this).prop("checked", !$(this).prop("checked"));
    });
});

http://jsfiddle.net/beC7q/

Could anyone please explain why the code above does not work?

Answer 1

If there are only two radio buttons

$('#toggler').click(function() {
    $('input[type="radio"]').not(':checked').prop("checked", true);
});

Demo: Fiddle

If there are more than 2 elements

var $radios = $('input[type="radio"][name="speeds"]')
$('#toggler').click(function() {
    var $checked = $radios.filter(':checked');
    var $next = $radios.eq($radios.index($checked) + 1);
    if(!$next.length){
        $next = $radios.first();
    }
    $next.prop("checked", true);
});

Demo: Fiddle