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Validation with input[type="radio"] return always false

I have an input[type="radio"], with no checked option by default, and i need to return false if none of these options are checked.
I'm exploring javascript only, so a jquery, angular or any other will be useles (at this moment).
I'm able to iterate over a radioObj and select its value, but i can't return false if no option is checked (actually, i can't return true)
not exactly what i have, but...
<input type="radio" id="rd1" name="radioGrp">opt1
<br>
<input type="radio" id="rd2" name="radioGrp">opt2
and in JS i have...
var rdObj = document.getElementByName("radioGrp");
var selectedValue;
for (var i = 0, length = rdObj.length; i < length; i++){
if(!rdObj[i].checked){
alert("Select one option");
return false;
}else{
//do something with value of radio checked value
}
}
This code always gives me the alert("Select one option"), no matter if i select one option or not.
Need for validation.
Any hel will be very appreciated

You probably want to wait for an event before you do any sort of value checking, otherwise your script will only run once, and at this point in time, nothing would have ever had the chance be checked.
You can attach a change event listener to each of your radios...
var myRadios = document.querySelectorAll('[name=radioGrp]');
var selectedValue;
myRadios.forEach(radio => {
radio.addEventListener('change', changeHandler);
})
function changeHandler(evt) {
// do some check in here
console.log(evt.target.value)
}
<input type="radio" id="rd1" name="radioGrp" value='opt1'>opt1
<br>
<input type="radio" id="rd2" name="radioGrp" value='opt2'>opt2
...or you can attach a submit event handler to your form and do some checking of your data then.
const myForm = document.querySelector('form');
myForm.addEventListener('submit', submitHandler);
function submitHandler(evt) {
evt.preventDefault();
const data = new FormData(evt.target);
const optionVal = data.get('radioGrp');
// do some check in here
if (!optionVal) {
console.log(`Please select a value`)
} else {
console.log(`Thanks for selecting ${optionVal}`)
}
}
<form>
<input type="radio" id="rd1" name="radioGrp" value='opt1'>opt1
<br>
<input type="radio" id="rd2" name="radioGrp" value='opt2'>opt2
<input type="submit">
</form>

You can try this:
function validateForm() {
var radios = document.getElementsByName("radioGrp");
var formValid = false;
for (var i = 0, length = radios.length; i < length; i++) {
if (radios[i].checked) {
formValid = true;
break;
}
}
if (!formValid) {
alert("Select one option");
}
return formValid;
}
<form name="form1" action="#" onsubmit="return validateForm();" method="post">
<input type="radio" id="rd1" name="radioGrp">opt1
<br>
<input type="radio" id="rd2" name="radioGrp">opt2
<br>
<input type="submit" value="Submit">
</form>

unselecting radio input selection

In a part of my application where i check for duplicate radio input selection and revert if its already selected to early selection.
Here is my html code ..
<input type="radio" name="A" checked="checked" onclick="return check();" />
<input type="radio" name="A" onclick="return check();" />
<br />
<input type="radio" name="B" onclick="return check();" />
<input type="radio" name="B" checked="checked" onclick="return check();" />
Here is the javascript code
function check() {
//logic to check for duplicate selection
alert('Its already selected');
return false;
}
And here is the demo
The above code works fine. The issue is when the input isn't initially checked. In such condition the radio input selection doesn't revert to unchecked.
NOTE: when in checked state, returning false shows and alert and sets the check box to initial checked state. But when initially in non checked state this doesn't work.

In DOM ready, check if any radio button is checked or not. If any radio button is checked, increase the counter by one. In onclick of the radio button, check if the counter value is 1. if yes, return false, else increase counter by 1.
try this code,
html
<input type="radio" name="A" checked="checked" />
<input type="radio" name="A" />
<br />
<input type="radio" name="B" />
<input type="radio" name="B" />
JS
var counterA = 0;
var counterB = 0;
$(document).ready(function () {
if ($("input:radio[name=A]").is(":checked") == true) counterA++;
if ($("input:radio[name='B']").is(":checked") == true) counterB++;
});
$('input:radio[name=A]').click(function () {
if (counterA == 1) {
alert('already checked');
return false;
} else {
counterA++;
}
});
$('input:radio[name=B]').click(function () {
if (counterB == 1) {
alert('already checked');
return false;
} else {
counterB++;
}
});
SEE THIS DEMO

iJay wants to ask several questions and privides the same answers for each question. Each answer can only be choosen once. If a user clicks the same answer the second time a error-message should be shown.
// get all elements
var elements = document.querySelectorAll('input[type="radio"]');
/**
* check if radio with own name is already selected
* if so return false
*/
function check(){
var selected_name = this.name,
selected_value = this.value,
is_valid = true;
// compare with all other elements
for(var j = 0; j < len; j++) {
var el = elements[j];
// does the elemenet have the same name AND is already selected?
if(el.name != selected_name && el.value == selected_value && el.checked){
// if so, selection is not valid anymore
alert('Oups..! You can not select this answer a second time :( Choose another one!')
// check current group for previous selection
is_valid = false;
break;
}
};
return is_valid;
}
/**
* bind your elements to the check-routine
*/
for(var i = 0, len = elements.length; i < len; i++) {
elements[i].onmousedown = check;
}
Here is a DEMO

Use $yourRadio.prop('checked', false); to uncheck the specific radio.

Use like this:
function check() {
//logic to check for duplicate selection
var checked = true ? false : true;
$(this).prop('checked', checked);
return false;
}

1) add class attribute to same type of checkbox elements(which are having same name)
ex: class = "partyA"
2)
var sourceIdsArr = new Array();
function check() {
$('.partyA').each(function() {
var sourceId = $(this).val();
if(sourceIdsArr.indexOf(sourceId) != -1){
sourceIdsArr.push(sourceId );
}
else{
alert('Its already selected');
return false;
}
});
}

Here is your code..
function check() {
//logic to check for duplicate selection
var selectflag=0;
var radiovalue=document.getElementsByName("B");
for(var i=0;i<radiovalue.length;i++)
{
// alert(radiovalue[i].checked);
if(radiovalue[i].checked==true)
{
selectflag=1;
break;
}
}
if(selectflag==1)
{
alert('Its already selected');
return false;
}
return true;
}
Trigger your event on MouseDown. It will work fine.

I think this is something you are looking for :
<html>
<head>
<script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
</head>
<body>
<input type="radio" name="A" checked="checked" onclick="return check(this);"/>
<input type="radio" name="A" onclick="return check(this);"/>
<script>
$( document ).ready(function() {
this.currentradio = $("input[name='A']:checked")[0];
});
function check(t) {
var newradio= $("input[name='A']:checked")[0];
if (newradio===document.currentradio){
alert('already selected');
return false
}else{
document.currentradio = $("input[name='A']:checked")[0];
}
}
</script>
</body>
<html>

Jquery Conditional Statements for Multiple Checkbox Values

I'm new to posting/stackoverflow, so please forgive me for any faux pas. I have multiple buttons and checkboxes that I need to store the values of to place into conditional statements.
The HTML code:
<h1>SECTION 1: GENDER</h1>
<p>What is your gender?</p>
<input type="button" onclick="storeGender(this.value)" value="Male"/>
<input type="button" onclick="storeGender(this.value)" value="Female"/>
<hr />
<h1>SECTION 2: AGE</h1>
<p>What is your age?</p>
<input type="button" onclick="storeAge(this.value)" value="18–22"/>
<input type="button" onclick="storeAge(this.value)" value="23–30"/>
<hr />
<h1>SECTION 3: TRAITS</h1>
<h3>Choose Two:</h3>
<form>
<input name="field" type="checkbox" value="1"/> Casual <br />
<input name="field" type="checkbox" value="10"/> Cheerful <br />
<input name="field" type="checkbox" value="100"/> Confident <br />
<input name="field" type="checkbox" value="1000"/> Tough <br />
<input type="button" id="storeTraits" value="SUBMIT" /> <br />
</form>
<hr />
<h2>Here is what I suggest</h2>
<p id="feedback">Feedback goes here.</p>
jQuery code:
// set up variables
var gender;
var age;
var string;
$(document).ready(function() {
startGame();
$("#storeTraits").click( function() {
serializeCheckbox();
}
); }
);
function startGame() {
document.getElementById("feedback").innerHTML = "Answer all the questions.";
}
function storeGender(value) {
gender = value;
}
function storeAge(value) {
age = value;
}
function serializeCheckbox() {
// clear out any previous selections
string = [ ];
var inputs = document.getElementsByTagName('input');
for( var i = 0; i < inputs.length; i++ ) {
if(inputs[i].type == "checkbox" && inputs[i].name == "field") {
if(inputs[i].checked == true) {
string.push(inputs[i].value);
}
}
}
checkFeedback();
}
//Limit number of checkbox selections
$(function(){
var max = 2;
var checkboxes = $('input[type="checkbox"]');
checkboxes.change(function(){
var current = checkboxes.filter(':checked').length;
checkboxes.filter(':not(:checked)').prop('disabled', current >= max);
});
});
function checkFeedback() {
if(gender == "Male") {
if (age == "18–22" && string == 11){
document.getElementById("feedback").innerHTML = "test1";
} else if (age == "18–22" && string == 110){
document.getElementById("feedback").innerHTML = "test2";
} else if (age == "18–22" && string == 1100){
document.getElementById("feedback").innerHTML = "test3";
} else if (age == "18–22" && string == 101){
document.getElementById("feedback").innerHTML = "test4";
}
}
}
I found this code on JSFiddle: http://jsfiddle.net/GNDAG/ which is what I want to do for adding together my trait values. However, when I try to incorporate it my conditional statements don't work. How do I add the code from the jsfiddle example and get the conditional statements to work? Thank you!

You need an integer, not a string array. Here's the code you need:
var traits = 0;
$('input[name=field]:checked').each(function () {
traits += parseInt($(this).val(), 10);
});
This will set the "traits" variable to an integer like 1, 11, 101, or 1001.
BTW: The second parameter to parseInt() is the base.
But a few suggestions:
Don't use "string" as a variable name.
Use radio buttons for gender and age.
Put all the input elements in the form.
Have one button that submits the form.
Attach a handler to the form submit event, and do your processing in that function, but call e.preventDefault() to prevent the form from submitting to the server. Alternatively, you could have the single button not be a submit button and attach an on-click handler to it.
Here's a jsfiddle with the code above and all the suggestions implemented.

jquery - Add exception onclick

I have the following input fields:
<input type="text" value="5" maxlength="12" id="qty" class="input-text qty" name="qty2050" tabindex="1">
and
<input type="text" value="0" maxlength="12" id="qty" class="input-text qty" name="qty2042" tabindex="1">
I use this code to prevent the user from losing inserted data (upon quitting the page):
<script>
window.onbeforeunload = function() {
var showAlert = false;
jQuery('.input-text.qty').each(function (){
//console.log("fonction 1");
var val = parseInt(jQuery(this).val(),10);
if(val > 0) { showAlert = true; }
//alert(val);
});
//console.log("fonction 2");
//console.log(showAlert);
if (showAlert == true) {
console.log("fonction 3");
return 'You have unsaved changes!';
}
}
</script>
I want to add an exception to my submit button, and to not show the alert message when there is a quantity > 0 in one of my input fields.
My problem is in adding this exception!
Thanks for help.

You can use bool confirmUnload. Like here: http://jonstjohn.com/node/23
<script>
var confirmUnload = true;
$("submit").click(function(){ confirmUnload = false; });
window.onbeforeunload = function() {
if (confirmUnload)
{
var showAlert = false;
jQuery('.input-text.qty').each(function (){
//console.log("fonction 1");
var val = parseInt(jQuery(this).val(),10);
if(val > 0) { showAlert = true; }
//alert(val);
});
//console.log("fonction 2");
//console.log(showAlert);
if (showAlert == true) {
console.log("fonction 3");
return 'You have unsaved changes!';
}
}
}
</script>

is this what you want:
<SCRIPT>
function checkForm(e) {
if (!(window.confirm("Do you want to submit the form?")))
e.returnValue = false;
}
</SCRIPT>
</HEAD>
<BODY>
<FORM name="theForm" action="0801.html"
onSubmit = "return checkForm(event)">
<INPUT type=submit>
</FORM>
your checks will go into the checkForm method in this case

Validation stuck at first validation

I'm new to JavaScript and my form validation works but keeps jumping to validate username on submit even when its validated. Heres my code
function validate_form(form)
{
var complete=false;
if(complete)
{
clear_all();
complete = checkUsernameForLength(form.username.value);
}
if(complete)
{
clear_all();
complete = checkaddress(form.country.value);
}
if(complete)
{
clear_all();
complete = checkaddress(form.country.value);
}
if(complete)
{
clear_all();
complete = checkEmail(form.email.value);
}
if (complete)
{
clear_all();
complete = checkphone(form.phone.value);
}
}
function clear_all()
{
document.getElementById('usernamehint').style.visibility= 'hidden';
/*.basicform.usernamehint.style.backgroundColor='white';*/
document.getElementById("countrthint").style.visibility= 'hidden';
/*document.basicform.countrthint.style.backgroundColor='white';*/
document.getElementById("subhint").style.visibility= 'hidden';
/*document.basicform.subject.style.backgroundColor='white';*/
document.getElementById("phonehint").style.visibility= 'hidden';
/*document.basicform.phone.style.backgroundColor='white';*/
document.getElementById("emailhint").style.visibility= 'hidden';
/*document.basicform.email.style.backgroundColor='white';*/
}
heres the functions
function checkUsernameForLength(whatYouTyped)
{
var fieldset = whatYouTyped.parentNode;
var txt = whatYouTyped.value;
if (txt.length > 2) {
fieldset.className = "welldone";
return true;
}
else
{
fieldset.className = "";
return false;
}
}
function checkEmail(whatYouTyped)
{
var fieldset = whatYouTyped.parentNode;
var txt = whatYouTyped.value;
if (/^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(txt))
{
fieldset.className = "welldone";
}
else
{
fieldset.className = "";
}
}
function checkaddress(whatYouTyped)
{
var fieldset = whatYouTyped.parentNode;
var txt = whatYouTyped.value;
if (txt.length > 3 && txt.length <10)
{
fieldset.className = "welldone";
}
else
{
fieldset.className = "";
}
}
function checkphone(whatYouTyped)
{
var fieldset = whatYouTyped.parentNode;
var txt = whatYouTyped.value;
if ( /^((\+\d{1,3}(-| )?\(?\d\)?(-| )?\d{1,5})|(\(?\d{2,6}\)?))(-| )?(\d{3,4})(-| )?(\d{4})(( x| ext)\d{1,5}){0,1}$/.test(txt)) {
fieldset.className = "welldone";
}
else
{
fieldset.className = "FAILS";
}
}
function addLoadEvent(func)
{
var oldonload = window.onload;
if (typeof window.onload != 'function')
{
window.onload = func;
} else {
window.onload = function()
{
oldonload();
func();
}
}
}
function prepareInputsForHints()
{
var inputs = document.getElementsByTagName("input");
for (var i=0; i<inputs.length; i++)
{
inputs[i].onfocus = function ()
{
this.parentNode.getElementsByTagName("span")[0].style.display = "inline";
}
inputs[i].onblur = function ()
{
this.parentNode.getElementsByTagName("span")[0].style.display = "none";
}
}
}
addLoadEvent(prepareInputsForHints);
and heres my form
<form form method="post" action="mailto:s00103684#mail.itsligo.ie" name="basicform" id="basicform" >
<fieldset>
<label for="username">Name:</label>
<input type="text" id="username" onkeyup="checkUsernameForLength(this);" />
<span class="hint" id="usernamehint">This Field Must Not Be Left Blank !</span>
</fieldset>
<fieldset>
<label for="country">Country:</label>
<input type="text" id="country" onkeyup="checkaddress(this);" />
<span class="hint" id="countryhint">This Field Must Not Be Left Blank !</span>
</fieldset>
<fieldset>
<label for="Subject">Subject:</label>
<input type="text" id="subject" onkeyup="checkaddress(this);" />
<span class="hint" id="subhint">Please Indicate What Your Interest Is !</span>
</fieldset>
<fieldset>
<label for="Phone">Phone:</label>
<input type="text" id="Phone" onkeyup="checkphone(this);" />
<span class="hint" id="phonehint">This Feld Must Be Numeric Values Only !</span>
</fieldset>
<fieldset>
<label for="email">Email Address:</label>
<input type="text" id="email" onkeyup="checkEmail(this);" />
<span class="hint" id="emailhint">You can enter your real address without worry - we don't spam!</span>
</fieldset>
<input value="send" type="button" onclick="validate_form(this.form)"/>
<br /><br /> <br /><br />
</form>
Please point amateur coder in right direction Thanks

Like others said, you are trying to access the username inside a condition, where the condition is always false. You set complete=false on start and right after that you try to see if that is true.
By the way, clear_all() may not have the behavior you want before the first validation. It will hide every input in the screen, so if there is anything else wrong, you won't be able to see that. I should go for hiding at the end (or at the beginning like #mplungjan stated, and always depending on what you need), maybe reusing your if(complete) structure:
function validate_form(form)
{
clear_all();
var complete = checkUsernameForLength(form.username.value);
if(complete)
{
complete = checkaddress(form.country.value);
}
if(complete)
{
complete = checkEmail(form.email.value);
}
if (complete)
{
complete = checkphone(form.phone.value);
}
}
Also, and after stating the username validation works, you should return a boolean value in the other methods =)
EDIT: Also, checking the errors the others said is a high priority issue.
EDIT2: I turned to see a repeated condition. Now I deleted it. To keep using the if(complete) that way, you should also do these changes:
function checkaddress(whatYouTyped)
{
var fieldset = whatYouTyped.parentNode;
var txt = whatYouTyped.value;
if (txt.length > 3 && txt.length <10)
{
fieldset.className = "welldone";
return true; // <-- this change
}
else
{
fieldset.className = "";
return false; // <-- and this change
}
}
Also, change the other methods to return true and false when you need.

Don't panic.
Everyone has to start somewhere and it can be very frustrating when you're only just learning the ropes.
In answering this question, we need to look not only at your JavaScript, but at the HTML as well.
You don't have a submit input type; instead opting for a regular button. That wouldn't necessarily be a problem, except nowhere in your JavaScript are you actually submitting your form. That means every time someone clicks the "Send" button, it will fire the validate_form() function you've defined but do nothing further with it. Let's make a couple of changes:
Replace your button with a submit input:
<input value="send" type="submit" />
Next, add the following code to your form tag so that we define an action to take when the user tries to submit your form:
onsubmit="validate_form(this)"
So your whole form tag now looks like this:
<form method="post" action="mailto:s00103684#mail.itsligo.ie" name="basicform" id="basicform" onsubmit="return validate_form(this)">
Notice I removed an extra "form" from that element.
Ok, next we want to handle what happens when the form is ready to be validated.
function validate_form(form)
{
// ...we can step through each item by name and validate its value.
var username = checkUsernameForLength(form["username"].value);
var email = checkaddress(form["country"].value);
// ...and so on.
return (username && email && {my other return values});
}
Each method you call (e.g. CheckUsernameForLength) should return either true or false, depending on whether the input is valid or not.
Our last return is probably a little inelegant, but is a verbose example of a way to aggregate our returned values and see if there are any "failed" values in there. If all your methods returned true, that last return will evaluate to true. Otherwise (obviously) it will return false.
The submission of the form will depend on whatever value is returned from your validate_form() function.

Please start with this ( http://jsfiddle.net/4aynr/4/ )
function validate_form(form)
{
var complete=false;
clear_all();
complete = checkUsernameForLength(form.username); // pass the FIELD here
if(complete)
{
complete = checkaddress(form.country.value);
}
if(complete)
{
complete = checkEmail(form.email.value);
}
if (complete)
{
complete = checkphone(form.phone.value);
}
if (!complete) alert('something went wrong')
return complete;
}
and change
<form form method="post" action="mailto:s00103684#mail.itsligo.ie"
name="basicform" id="basicform" >
to
<form method="post" action="mailto:s00103684#mail.itsligo.ie"
name="basicform" id="basicform"
onSubmit="return validate_form(this)">
and change
<input value="send" type="button" onclick="validate_form(this.form)"/>
to
<input value="send" type="submit" />