How to get the selected radio button’s value? [duplicate]

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>

Ignorance

@Machavity: this isn't the duplicate. The other question is the duplicate. – Lives

Answer 1

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.

Spearwort

That was working for jquery 1.7 but now the correct syntax for jQuery 1.9 is $('input[name="genderS"]:checked').val(); (remove the @) – Dishcloth

I believe the @ syntax was deprecated even earlier than that (jquery 1.2) – Monophysite

@TomPietrosanti the documentation appears to be a little off, jsfiddle.net/Xxxd3/608 works in <1.7.2 but not in >1.8.3. Regardless, the @ should definitely be removed – Spearwort

Yeah, it looks like they left some backwards compatibility in there, but didn't update the docs to match. I remember some hoopla when they dropped some deprecated features that were still widely in use, so they added support back in. Maybe that's why... – Monophysite

document.querySelector() should probably be the recommended approach in straight JavaScript now. – Superclass

for...of is supported by all modern browsers, and is a little easer to read / understand. so for (let radio of radios) { \\do stuff } – Deviltry

const checkedRadio = radios.find(({ checked }) => checked); will get the first (and only, in this case) input with truthy checked. If there is a chance that none is checked, you'll want to make sure that checkedRadio is not null. – Avent

Answer 2

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.

Alys

Using document.querySelector() is a pure javascript answer: developer.mozilla.org/en-US/docs/Web/API/document.querySelector – Regal

If you store it in a variabel and no radiobutton is selected you cause the browser to stop. Console says: TypeError document.querySelector(...) is null. – Dionysiac

That does only work if one is selected. So you should check it before. var selector = document.querySelector('input[name="genderS"]:checked'); if(selector) console.log(selector.value); – Zaxis

I'm working with Templates in Meteor,and that :checked trick totally nailed it for me.. for me the fix to reading radio buttons from a Meteor Template form was accountType = template.find("[name='optradio']:checked").value; – Whiteness

And you can use it in jQuery by using:$('input[name="genderS"]:checked').val() – Luciennelucier

Answer 3

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

Demmer

This works too: document.forms.your-form-name.name-shared-by-radio-buttons.value – Tetanus

I think most people are overlooking this. The accepted answer works. Giorgos Tsakonas answer is better. But this one is the fundamentally correct answer. This one is how radio buttons actually work. Note that if nothing has been selected, it returns an empty string. – Clipclop

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 @).

Dishcloth

Answer 5

ECMAScript 6 version

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

Bomar

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);

Desimone

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

Inescutcheon

I really guess this is the preferred way to go today. One might however also select the form via querySelector, which works fine too: const form = document.querySelector('form[name="somename"]'). Also one can set the value of radios with radios.value = {value} However, selecting the radios directly (e.g. document.querySelectorAll('input[name="some_radio"]')) will not work, because it returns NodeList instead of RadioNodeList. This is why you have to select the form first. – Wycoff

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.

Agnesagnese

eval is not the best option here... you might want to say var sizes = document.theForm[field]; and delete the first assignment, so not using test variable anymore. – Engedus

For my knowledge, would eval work as is? Or would it work only with eval('var sizes=document.theForm.' + field) ? – Agnesagnese

the eval statement in your answer var sizes = eval(test); would work that way (i just testet it in firebug). – Engedus

That makes more sense, but I'm getting an error "Unexpected token [" on that line where I put field in brackets. Any guesses as to why? – Ignorance

Answer 9

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.

Malloy

Answer 10

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.

Swim

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

Wycoff

+1. Well explained. I was looking for an answer explaining the difference between using elements and using the shortcut variant. Thanks for that! Does the shortcut variant work on all major browsers? – Poul

What works for me is document.querySelector('input[name=color]:checked'), as someone said below ` – Fornax

Answer 12

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
}

Hartzog

Answer 13

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

Cochineal

Answer 14

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");

Pica

Answer 15

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.

Asuncionasunder

Answer 16

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

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

Luge

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>

Pires

this kind of works, but it doesn't update the value whenever you select "regular crust". it only shows the default value that it loads with – Euhemerism

@Euhemerism 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 – Pires

yeah. thanks for following up and sharing that. i think this answer is incomplete without that. – Euhemerism

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">

Cutlerr

Answer 19

const radiopropertys = document.querySelectorAll('#property');//Id or Class

            radiopropertys.forEach(radioproperty => {
                if (radioproperty.value != '' && radioproperty.checked) {
                    //do something
                }
            })

Kusin

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Answer 20

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

Outstretch