How to get the selected radio button’s value?

Question

I’m having some strange problem with my JS program. I had this working properly but for some reason it’s no longer working. I just want to find the value of the radio button (which one is selected) and return it to a variable. For some reason it keeps returning undefined.

Here is my code:

function findSelection(field) {
    var test = 'document.theForm.' + field;
    var sizes = test;

    alert(sizes);
        for (i=0; i < sizes.length; i++) {
            if (sizes[i].checked==true) {
            alert(sizes[i].value + ' you got a value');     
            return sizes[i].value;
        }
    }
}

submitForm:

function submitForm() {

    var genderS =  findSelection("genderS");
    alert(genderS);
}

HTML:

<form action="#n" name="theForm">

    <label for="gender">Gender: </label>
    <input type="radio" name="genderS" value="1" checked> Male
    <input type="radio" name="genderS" value="0" > Female<br><br>
    <a href="javascript: submitForm()">Search</A>
</form>

Answer 1

This works with any explorer.

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

This is a simple way to get the value of any input type. You also do not need to include jQuery path.

Answer 2

You can do something like this:

var radios = document.getElementsByName('genderS');

for (var i = 0, length = radios.length; i < length; i++) {
  if (radios[i].checked) {
    // do whatever you want with the checked radio
    alert(radios[i].value);

    // only one radio can be logically checked, don't check the rest
    break;
  }
}

<label for="gender">Gender: </label>
<input type="radio" name="genderS" value="1" checked="checked">Male</input>
<input type="radio" name="genderS" value="0">Female</input>

jsfiddle

Edit: Thanks HATCHA and jpsetung for your edit suggestions.

Answer 3

document.forms.your-form-name.elements.radio-button-name.value

Answer 4

Since jQuery 1.8, the correct syntax for the query is

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

Not $('input[@name="genderS"]:checked').val(); anymore, which was working in jQuery 1.7 (with the @).

Answer 5

ECMAScript 6 version

let genderS = Array.from(document.getElementsByName("genderS")).find(r => r.checked).value;

Answer 6

Here's a nice way to get the checked radio button's value with plain JavaScript:

const form = document.forms.demo;
const checked = form.querySelector('input[name=characters]:checked');

// log out the value from the :checked radio
console.log(checked.value);

Source: https://ultimatecourses.com/blog/get-value-checked-radio-buttons

Using this HTML:

<form name="demo">
  <label>
    Mario
    <input type="radio" value="mario" name="characters" checked>
  </label>
  <label>
    Luigi
    <input type="radio" value="luigi" name="characters">
  </label>
  <label>
    Toad
    <input type="radio" value="toad" name="characters">
  </label>
</form>

You could also use Array Find the checked property to find the checked item:

Array.from(form.elements.characters).find(radio => radio.checked);

Answer 7

In case someone was looking for an answer and landed here like me, from Chrome 34 and Firefox 33 you can do the following:

var form = document.theForm;
var radios = form.elements['genderS'];
alert(radios.value);

or simpler:

alert(document.theForm.genderS.value);

refrence: https://developer.mozilla.org/en-US/docs/Web/API/RadioNodeList/value

Answer 8

Edit: As said by Chips_100 you should use :

var sizes = document.theForm[field];

directly without using the test variable.

---

Old answer:

Shouldn't you eval like this ?

var sizes = eval(test);

I don't know how that works, but to me you're only copying a string.

Answer 9

This is pure JavaScript, based on the answer by @Fontas but with safety code to return an empty string (and avoid a TypeError) if there isn't a selected radio button:

var genderSRadio = document.querySelector("input[name=genderS]:checked");
var genderSValue = genderSRadio ? genderSRadio.value : "";

The code breaks down like this:

• Line 1: get a reference to the control that (a) is an <input> type, (b) has a name attribute of genderS, and (c) is checked.
• Line 2: If there is such a control, return its value. If there isn't, return an empty string. The genderSRadio variable is truthy if Line 1 finds the control and null/falsey if it doesn't.

For JQuery, use @jbabey's answer, and note that if there isn't a selected radio button it will return undefined.

Answer 10

Try this

function findSelection(field) {
    var test = document.getElementsByName(field);
    var sizes = test.length;
    alert(sizes);
    for (i=0; i < sizes; i++) {
            if (test[i].checked==true) {
            alert(test[i].value + ' you got a value');     
            return test[i].value;
        }
    }
}


function submitForm() {

    var genderS =  findSelection("genderS");
    alert(genderS);
    return false;
}

A fiddle here.

Answer 11

First, shoutout to ashraf aaref, who's answer I would like to expand a little.

As MDN Web Docs suggest, using RadioNodeList is the preferred way to go:

// Get the form
const form = document.forms[0];

// Get the form's radio buttons
const radios = form.elements['color'];

// You can also easily get the selected value
console.log(radios.value);

// Set the "red" option as the value, i.e. select it
radios.value = 'red';

One might however also select the form via querySelector, which works fine too:

const form = document.querySelector('form[name="somename"]')

However, selecting the radios directly will not work, because it returns a simple NodeList.

document.querySelectorAll('input[name="color"]')
// Returns: NodeList [ input, input ]

While selecting the form first returns a RadioNodeList

document.forms[0].elements['color']
// document.forms[0].color # Shortcut variant
// document.forms[0].elements['complex[naming]'] # Note: shortcuts do not work well with complex field names, thus `elements` for a more programmatic aproach
// Returns: RadioNodeList { 0: input, 1: input, value: "red", length: 2 }

This is why you have to select the form first and then call the elements Method. Aside from all the input Nodes, the RadioNodeList also includes a property value, which enables this simple manipulation.

Reference: https://developer.mozilla.org/en-US/docs/Web/API/RadioNodeList/value

Answer 12

Here is an Example for Radios where no Checked="checked" attribute is used

function test() {
var radios = document.getElementsByName("radiotest");
var found = 1;
for (var i = 0; i < radios.length; i++) {       
    if (radios[i].checked) {
        alert(radios[i].value);
        found = 0;
        break;
    }
}
   if(found == 1)
   {
     alert("Please Select Radio");
   }    
}

DEMO : http://jsfiddle.net/ipsjolly/hgdWp/2/ [Click Find without selecting any Radio]

Source (from my blog): http://bloggerplugnplay.blogspot.in/2013/01/validateget-checked-radio-value-in.html

Answer 13

Putting Ed Gibbs' answer into a general function:

function findSelection(rad_name) {
    const rad_val = document.querySelector('input[name=' + rad_name + ']:checked');
    return (rad_val ? rad_val.value : "");
}

Then you can do findSelection("genderS");

Answer 14

lets suppose you need to place different rows of radio buttons in a form, each with separate attribute names ('option1','option2' etc) but the same class name. Perhaps you need them in multiple rows where they will each submit a value based on a scale of 1 to 5 pertaining to a question. you can write your javascript like so:

<script type="text/javascript">

    var ratings = document.getElementsByClassName('ratings'); // we access all our radio buttons elements by class name     
    var radios="";

    var i;
    for(i=0;i<ratings.length;i++){
        ratings[i].onclick=function(){
            var result = 0;
            radios = document.querySelectorAll("input[class=ratings]:checked");
            for(j=0;j<radios.length;j++){
                result =  result + + radios[j].value;
            }
            console.log(result);
            document.getElementById('overall-average-rating').innerHTML = result; // this row displays your total rating
        }
    }
</script>

I would also insert the final output into a hidden form element to be submitted together with the form.

Answer 15

I like to use brackets to get value from input, its way more clear than using dots.

document.forms['form_name']['input_name'].value;

Answer 16

I realize this is extremely old, but it can now be done in a single line

function findSelection(name) {
    return document.querySelector(`[name="${name}"]:checked`).value
}

Answer 17

I prefer to use a formdata object as it represents the value that should be send if the form was submitted.

Note that it shows a snapshot of the form values. If you change the value, you need to recreate the FormData object. If you want to see the state change of the radio, you need to subscribe to the change event change event demo

Demo:

let formData = new FormData(document.querySelector("form"));
console.log(`The value is: ${formData.get("choice")}`);

<form>
    <p>Pizza crust:</p>
    <p>
        <input type="radio" name="choice" value="regular" >
        <label for="choice1id">Regular crust</label>
    </p>
    <p>
        <input type="radio" name="choice" value="deep" checked >
        <label for="choice2id">Deep dish</label>
    </p>
</form>

Answer 18

If it is possible for you to assign a Id for your form element(), this way can be considered as a safe alternative way (specially when radio group element name is not unique in document):

function findSelection(field) {
    var formInputElements = document.getElementById("yourFormId").getElementsByTagName("input");
    alert(formInputElements);
        for (i=0; i < formInputElements.length; i++) {
        if ((formInputElements[i].type == "radio") && (formInputElements[i].name == field) && (formInputElements[i].checked)) {
            alert(formInputElements[i].value + ' you got a value');     
            return formInputElements[i].value;
        }
    }
}

HTML:

<form action="#n" name="theForm" id="yourFormId">

Answer 19

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