How can we access the value of a radio button using the DOM?
For eg. we have the radio button as :
<input name="sex" type="radio" value="male">
<input name="sex" type="radio" value="female">
They are inside a form with name form1. When I try
document.getElementByName("sex").value
it returns 'male' always irrespective of the checked value.
There are a couple of ways.
<input name="sex" id="sex_male" type="radio" value="male">
<input name="sex" id="sex_female" type="radio" value="female">
Then you can use document.getElementById("sex_male")
Then you can do something like this:
//This loops over all input elements that have a name of "sex"
$$('input[name="sex"]').each( function(elem) {
//Do something
});
Or even this to get at just the "male" radio button:
$$('input[name="sex"][value="male"]').each(function(elem) {
//Do something
});
An easy way to get started with Prototype is include it from Google by adding this between the <head></head> tags of your page:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/prototype/1.6.0.3/prototype.js"></script>
If you use document.form1.sex, you are returned an array.
document.form1.sex[0] = first radio button
document.form1.sex[1] = second radio button
To check which is checked you need to loop:
whoChecked(document.form1.sex)
funtcion whoChecked(fieldName) {
for(var x=0;x<fieldName.length;x++) {
if(fieldName[x].checked) {
return fieldname[x].value
}
}
If you need the selected one, most frameworks support functionality like this:
//jQuery
$("input[name='sex']:checked").val()
var list = document.getElementsByName('sex');
for(var i=0;i<list.length;i++){
if(list[i].type=='radio' && list[i].checked){
alert(list[i].value);
break;
}
}
document.getElementByName("sex").value
You mean getElementsByName('sex')[0].value? (There's no ‘getElementByName’.)
That will of course always pick the first input element with that name — the one whose value is indeed male. You then check to see if it's selected by using the ‘.checked’ property.
For this simple case you can get away with:
var sex= document.getElementsByName("sex")[0].checked? 'male' : 'female';
For the general case you have to loop over each radio input to see which is checked. It would probably be better to get the form object first (putting an id on the form and using document.getElementById is generally better than using the ‘name’-based document.forms collection), and then access form.elements.sex to get the list, in case there are any other elements on the page that have ‘name="sex"’ attributes (potentially other things than form fields).
You can get your selected radio's value by this method :
<script>
function getRadioValue()
{
for (var i = 0; i < document.getElementsByName('sex').length; i++)
{
if (document.getElementsByName('sex')[i].checked)
{
return document.getElementsByName('sex')[i].value;
}
}
}
</script>
If you want the selected one, but don't have a framework handy, you can iterate over the element array looking for whichever one is checked:
for (var i = 0; i < document.form1.sex.length; i++) {
if (document.form1.sex[i].checked) alert(document.form1.sex[i].value);
}