make a input field required if radio is checked

Question

Can I somehow insert the required attribute into an input field only if a certain radio is checked?

I have an input field named \"ladder-meters\" that is not require

Answer 1

Easy to achieve with jQuery:

$('#ladder').change(function () {
    if($(this).is(':checked') {
        $('#ladder-meters').attr('required');
    } else {
        $('#ladder-meters').removeAttr('required');
    }
});