How to get value of selected radio button?

I want to get the selected value from a group of radio buttons.

Here's my HTML:

<div id="rates">
  <input type="radio" id="r1" name="rate" value="Fixed Rate"> Fixed Rate
  <input type="radio" id="r2" name="rate" value="Variable Rate"> Variable Rate
  <input type="radio" id="r3" name="rate" value="Multi Rate" checked="checked"> Multi Rate  
</div>

Here's my js:

var rates = document.getElementById('rates').value;
var rate_value;
if(rates =='Fixed Rate'){
	rate_value = document.getElementById('r1').value;
	
}else if(rates =='Variable Rate'){
	rate_value = document.getElementById('r2').value;
	
}else if(rates =='Multi Rate'){
	rate_value = document.getElementById('r3').value;
}  

document.getElementById('results').innerHTML = rate_value;

I keep getting undefined.

This works in IE9 and above and all other browsers.

document.querySelector('input[name="rate"]:checked').value;

var rates = document.getElementById('rates').value;

The rates element is a div, so it won't have a value. This is probably where the undefined is coming from.

The checked property will tell you whether the element is selected:

if (document.getElementById('r1').checked) {
  rate_value = document.getElementById('r1').value;
}

Or

$("input[type='radio'][name='rate']:checked").val();

You can get the value by using the checked property.

var rates = document.getElementsByName('rate');
var rate_value;
for(var i = 0; i < rates.length; i++){
    if(rates[i].checked){
        rate_value = rates[i].value;
    }
}

For you people living on the edge:

There is now something called a RadioNodeList and accessing it's value property will return the value of the currently checked input. This will remove the necessity of first filtering out the 'checked' input as we see in many of the posted answers.

Example Form

<form id="test">
<label><input type="radio" name="test" value="A"> A</label>
<label><input type="radio" name="test" value="B" checked> B</label>
<label><input type="radio" name="test" value="C"> C</label>
</form>

To retrieve the checked value, you could do something like this:

var form = document.getElementById("test");
alert(form.elements["test"].value);

The JSFiddle to prove it: http://jsfiddle.net/vjop5xtq/

Please note this was implemented in Firefox 33 (All other major browser seems to support it). Older browsers will require a polfyill for RadioNodeList for this to properly function

Another (apparently older) option is to use the format: "document.nameOfTheForm.nameOfTheInput.value;" e.g. document.mainForm.rads.value;

document.mainForm.onclick = function(){
    var radVal = document.mainForm.rads.value;
    result.innerHTML = 'You selected: '+radVal;
}

<form id="mainForm" name="mainForm">
    <input type="radio" name="rads" value="1" />
    <input type="radio" name="rads" value="2" />
    <input type="radio" name="rads" value="3" />
    <input type="radio" name="rads" value="4" />
</form>
<span id="result"></span>

You can refer to the element by its name within a form. Your original HTML does not contain a form element though.

Fiddle here (works in Chrome and Firefox): https://jsfiddle.net/Josh_Shields/23kg3tf4/1/

The one worked for me is given below from api.jquery.com.

HTML

<input type="radio" name="option" value="o1">option1</input>
<input type="radio" name="option" value="o2">option2</input>

JavaScript

var selectedOption = $("input:radio[name=option]:checked").val()

The variable selectedOption will contain the value of the selected radio button (i.e) o1 or o2

Use document.querySelector('input[type = radio]:checked').value; to get value of selected checkbox , you can use other attributes to get value like name = gender etc. please go through below snippet definitely it will helpful to you,

Solution

document.mainForm.onclick = function(){
    var gender = document.querySelector('input[name = gender]:checked').value;
    result.innerHTML = 'You Gender: '+gender;
}

<form id="mainForm" name="mainForm">
    <input type="radio" name="gender" value="Male" checked/>Male
    <input type="radio" name="gender" value="Female" />Female
    <input type="radio" name="gender" value="Others" />Others
</form>
<span id="result"></span>

Thank-You

HTML CODE:

<input type="radio" name="rdoName" value="YES"/> <input type="radio" name="rdoName" value="NO"/>

JQUERY CODE:

var value= $("input:radio[name=rdoName]:checked").val();

$("#btnSubmit").click(function(){
var value=$("input:radio[name=rdoName]:checked").val();
console.log(value);
alert(value);
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="radio" name="rdoName" value="YES"/> YES
<input type="radio" name="rdoName" value="NO"/> NO
<br/>
<input type="button"id="btnSubmit"value="Which one Selected"/>

You will get

value="YES" //if checked Radio Button with the value "YES"
value="NO" //if checked Radio Button with the value "NO"

If you are using javascript without jQuery, you can use this command :

document.querySelector("input[type='radio'][name=rate]:checked").value;

In Javascript we can get the values by using Id's "getElementById()" in the above code you posted has contain name not Id so you to modify like this

if (document.getElementById('r1').checked) {
  rate_value = document.getElementById('r1').value;
}

use this rate_value according to your code

Shortest

[...rates.children].find(c=>c.checked).value

let v= [...rates.children].find(c=>c.checked).value

console.log(v);

<div id="rates">
  <input type="radio" id="r1" name="rate" value="Fixed Rate"> Fixed Rate
  <input type="radio" id="r2" name="rate" value="Variable Rate"> Variable Rate
  <input type="radio" id="r3" name="rate" value="Multi Rate" checked="checked"> Multi Rate  
</div>

A year or so has passed since the question was asked, but I thought a substantial improvement of the answers was possible. I find this the easiest and most versatile script, because it checks whether a button has been checked, and if so, what its value is:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Check radio checked and its value</title>
</head>
<body>

    <form name="theFormName">
        <input type="radio" name="theRadioGroupName" value="10">
        <input type="radio" name="theRadioGroupName" value="20">
        <input type="radio" name="theRadioGroupName" value="30">
        <input type="radio" name="theRadioGroupName" value="40">
        <input type="button" value="Check" onclick="getRadioValue('theRadioGroupName')">
    </form>

    <script>
        function getRadioValue(groupName) {
            var radios = theFormName.elements[groupName];
            window.rdValue; // declares the global variable 'rdValue'
            for (var i=0; i<radios.length; i++) {
                var someRadio = radios[i];
                if (someRadio.checked) {
                    rdValue = someRadio.value;
                    break;
                }
                else rdValue = 'noRadioChecked';
            }
            if (rdValue == '10') {
                alert('10'); // or: console.log('10')
            }
            else if (rdValue == 'noRadioChecked') {
                alert('no radio checked');
            }
        }
    </script>
</body>
</html>

You can also call the function within another function, like this:

function doSomething() {
    getRadioValue('theRadioGroupName');
    if (rdValue == '10') {
        // do something
    }
    else if (rdValue == 'noRadioChecked') {
        // do something else
    }  
} 

Assuming your form element is referred to by myForm variable below, and that your radio buttons share the name "my-radio-button-group-name", the following is pure JavaScript and standards compliant (although I have not checked it to be available everywhere):

myForm.elements.namedItem("my-radio-button-group-name").value

The above will yield the value of a checked (or selected, as it is also called) radio button element, if any, or null otherwise. The crux of the solution is the namedItem function which works with radio buttons specifically.

See HTMLFormElement.elements, HTMLFormControlsCollection.namedItem and especially RadioNodeList.value, as namedItem usually returns a RadioNodeList object.

I use MDN because it allows one to track standards compliance, at least to a large degree, and because it is easier to comprehend than many WhatWG and W3C publications.

directly calling a radio button many times gives you the value of the FIRST button, not the CHECKED button. instead of looping thru radio buttons to see which one is checked, i prefer to call an onclick javascript function that sets a variable that can later be retrieved at will.

<input type="radio" onclick="handleClick(this)" name="reportContent" id="reportContent" value="/reportFleet.php" >

which calls:

var currentValue = 0;
function handleClick(myRadio) {
	currentValue = myRadio.value;
    document.getElementById("buttonSubmit").disabled = false; 
}

additional advantage being that i can treat data and/or react to the checking of a button (in this case, enabling SUBMIT button).

You can also loop through the buttons with a forEach-loop on the elements

    var elements = document.getElementsByName('radioButton');
    var checkedButton;
    console.log(elements);
    elements.forEach(e => {
        if (e.checked) {
            //if radio button is checked, set sort style
            checkedButton = e.value;
        }
    });

An improvement to the previous suggested functions:

function getRadioValue(groupName) {
	var _result;
	try {
		var o_radio_group = document.getElementsByName(groupName);
		for (var a = 0; a < o_radio_group.length; a++) {
			if (o_radio_group[a].checked) {
				_result = o_radio_group[a].value;
				break;
			}
		}
	} catch (e) { }
	return _result;
}

You can use .find() to select checked element:

var radio = Array.from(document.querySelectorAll('#rate input'))

var value = radio.length && radio.find(r => r.checked).value

My take on this problem with pure javascript is to find the checked node, find its value and pop it out from the array.

var Anodes = document.getElementsByName('A'),
    AValue = Array.from(Anodes)
       .filter(node => node.checked)
       .map(node => node.value)
       .pop();
console.log(AValue);

Note that I'm using arrow functions. See this fiddle for a working example.

If you are using jQuery:

$('input[name="rate"]:checked').val();

Here is a solution putting the radio buttons in a constant and getting the selected value only when needed.

const rates = document.forms.rates.elements["rate"]
showRate()
function showRate(){
    document.getElementById('results').innerHTML = rates.value
}

<form id="rates" onchange="showRate()">
  <input type="radio" id="r1" name="rate" value="Fixed Rate"> Fixed Rate
  <input type="radio" id="r2" name="rate" value="Variable Rate"> Variable Rate
  <input type="radio" id="r3" name="rate" value="Multi Rate" checked="checked"> Multi Rate 
</form>
<div id="results"></div>

<form id="rates">
  <input type="radio" name="rate" value="Fixed Rate"> Fixed
  <input type="radio" name="rate" value="Variable Rate"> Variable
  <input type="radio" name="rate" value="Multi Rate" checked> Multi
</form>

then...

var rate_value = rates.rate.value;

check value by ID:

var CheckedValues = ($("#r1").is(':checked')) ? 1 : 0;

I used the jQuery.click function to get the desired output:

$('input[name=rate]').click(function(){
  console.log('Hey you clicked this: ' + this.value);
  
  if(this.value == 'Fixed Rate'){
    rate_value = $('#r1').value;
  } else if(this.value =='Variable Rate'){
   rate_value = $('#r2').value;
  } else if(this.value =='Multi Rate'){
   rate_value = $('#r3').value;
  }  

  $('#results').innerHTML = rate_value;
});

Hope it helps.

If the buttons are in a form
var myform = new FormData(getformbywhatever); myform.get("rate");
QuerySelector above is a better solution. However, this method is easy to understand, especially if you don't have a clue about CSS. Plus, input fields are quite likely to be in a form anyway.
Didn't check, there are other similar solutions, sorry for the repetition

var rates = document.getElementById('rates').value;

cannot get values of a radio button like that instead use

rate_value = document.getElementById('r1').value;

If you are using the JQuery, please use the bellow snippet for group of radio buttons.

var radioBtValue= $('input[type=radio][name=radiobt]:checked').val();

Simply use: document.querySelector('input[rate][checked]').value

https://codepen.io/anon/pen/YQxbZJ

The HTML

<div id="rates">
<input type="radio" id="x1" name="rate" value="Fixed Rate"> Fixed Rate
<input type="radio" id="x2" name="rate" value="Variable Rate" 
checked="checked"> Variable Rate
<input type="radio" id="x3" name="rate" value="Multi Rate" > Multi Rate
</div>

<button id="rdio"> Check Radio </button>
<div id="check">

</div>

The JS

var x ,y;
var x = document.getElementById("check");
function boom()
{
if (document.getElementById("x1").checked)
  y = document.getElementById("x1").value;

else if(document.getElementById("x2").checked)
  y = document.getElementById("x2").value;

else if (document.getElementById("x3").checked)
  y = document.getElementById("x3").value;
else
  y = "kuch nhi;"
x.innerHTML = y;
}

var z = document.getElementById('rdio');
z.addEventListener("click", boom);`

   var rates=document.getElementsByName("rate");
            for (i = 0; i < rates.length; i++) {
            if (rates[i].checked) {
              console.log(rates[i].value);
              rate=rates[i].value;
              document.getElementById("rate").innerHTML = rate;
              alert(rate);
              
            }
          }

        <div id="rates">
          <input type="radio" id="r1" name="rate" value="Fixed Rate"> Fixed Rate
          <input type="radio" id="r2" name="rate" value="Variable Rate"> Variable Rate
          <input type="radio" id="r3" name="rate" value="Multi Rate" checked="checked"> Multi Rate  
        </div>
        </br>
        <div id='rate'>
        </div>

In php it's very easy
html page

Male<input type="radio" name="radio" value="male"><br/>
Female<input type="radio" name="radio" value="female"><br/>
Others<input type="radio" name="radio" value="other"><br/>
<input type="submit" value="submit">

Take value from form to php

$radio=$_POST['radio'];<br/>
use php if(isset($_POST['submit']))<br/>
{<br/>
echo "you selected".$radio."thank u";<br/>
}