Struts finding checked radio button

Question

I created a radio button in struts however i saw the radio button accepts a list so i provided a list {true:'Yes',false:'No'}. This creates a radio button pair with Yes and No labels however i would like to use javascript to get the radio button thats checked.

When the radio buttons are created they are give Id's with 'name'true and 'name'false. I am confused as to how i will use javascript to get the checked radio button and its value. Under is my code:

Struts Radio Button

<s:radio name="over18" id= "over18Stat" list="#{true:'Yes',false:'No'}" 
                onclick="Over18Changed(this.value)"/>

Javascript

I have tried this however it does not work

var ofage = document.getElementByName('over18').value ;

Answer 1

The getElementsByTagName is plural as it returns a (possibly empty) NodeList of elements that match the given name.

To get the selected button, loop over the NodeList (I've turned it into a function):

function getCheckedButton(name) {
  var buttons = document.getElementsByName(name);

  for (var i=0; i<buttons.length; i++) {

  if (buttons[i].checked) {
    return buttons[i];
  }
}

If you just want the button's value:

 return buttons[i].value

You could also use querySelector:

function getCheckedValue(name) {
  var button =  document.querySelector('input[name=' + name + ']:checked');
  return button && button.value;
}

However, querySelector isn't supported by all browsers in use and complex selectors aren't supported by all those that support querySelector.