problem with radio button and javascript

**dominant** · Jul 29, 2003, 01:01

I cannot see the value of the <input type="radio".....
through the javascript code

**xDev** · Jul 29, 2003, 01:56

Hi,

Since you didn't post your code I have no way of knowing what your doing wrong, but try this and see if it sheds any light on your problem.

Code:

<html>
<head>

<script type="text/javascript">
function getRadioVals(el) {
  var str = '', i = 0;
  for(i; i < el.length; i++)
  {
    str += 
    'Value of radio '+i+': ' 
    + '"' + el[i].value + '"' + 
    '\n\t checked = '
    + el[i].checked + '\n';
  }
  alert(str);
}
</script>

</head>

<body>

<form name="f">
<input type="radio" name="radios" value="val0" /> 1<br />
<input type="radio" name="radios" value="val1" checked="checked" /> 2<br />
<input type="radio" name="radios" value="val2" /> 3<br />
<input type="radio" name="radios" value="val3" /> 4<br />
</form>

<a href="#" onclick="getRadioVals(document.f.radios); return false;">get Radio Properties</a>

</body>
</html>

-xDev

**dominant** · Jul 29, 2003, 03:04

Code:

<script>
function check() {

var radioValue=document.formName.radios.value;

alert(radioValue);
}
</script>
.....
....
<input type="radio" name="radios" value="1">

i cannot see the value on the alert function, but only undefined

**xDev** · Jul 29, 2003, 03:13

Originally Posted by dominant

Code:

<script>
function check() {

var radioValue=document.formName.radios.value;

alert(radioValue);
}
</script>
.....
....
<input type="radio" name="radios" value="1">

i cannot see the value on the alert function, but only undefined

Radio buttons are collections. They work the same as arrays. What you want is document.formName.radios[0].value

That's why in my example code I looped through my 4 radio buttons to show you that radio button are indeed arrays. Did you try the code?

e.g:

Code:

<input type="radio" name="radios" value="1">
<input type="radio" name="radios" value="2">

If you want to get the value of the second radio button, it would be:
document.formName.radios[1].value, which is 2!

Arrays start at index 0, so your first radio button value is always referenced as document.formName.radioButtonGroupName[0].value, or in the case of the above code:

document.formName.radios[0].value

Some links for you:
http://www.devguru.com/Technologies/...ref/radio.html

http://devedge.netscape.com/library/...nce/radio.html

http://tech.irt.org/articles/js216/index11.htm

http://www.jennifermadden.com/162/ex...loopRadio.html

-xDev

**dominant** · Jul 29, 2003, 04:31

Thank you for your help!

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