Develop Reference

Javascript check a radio button in form based on a text box value

I have a form which inserts and retrieves data from a google sheet.
Example:
I have two radio buttons on my form
<input id="Rdio_1" name="RdioSelect" type="radio" class="FirstCheck"
value="1" onchange="RadioValInsert ()"/>
<input id="Rdio_2" name="RdioSelect" type="radio" class="FirstCheck"
value="2" onchange="RadioValInsert ()" />
when the above is clicked the value of the radio button is stored in a text box..the RadioValInsert () does it
<input type="text" id="DatafromRadio" name="DatafromRadio">
I am able to insert this value of 1 or 2 into the corresponding cell in google sheet.
When I want to EDIT it, I retrieve the data and the Textbox value is 1 or 2
The button which retrieves the data has a function to check the corresponding radio button based on the value of the Text box.
function RadioChk() {
var val = document.getElementById("DatafromRadio").value;
if (val == 1) {
document.getElementById("Rdio_1").checked = true;
}
if (val == 2) {
document.getElementById("Rdio_2").checked = true;
}
}
This is not working
Thanks in advance for your help

You are doing your check and uncheck related code inside RadioChk function however you haven't bind click event on radio inputs . If i correctly understood your question , here is how you can select and deselect your radio buttons.
function RadioValInsert() {
console.log('checked');
var val = document.getElementById("DatafromRadio").value;
if(val ==1 || val ==2){
uncheckAll();
document.getElementById("Rdio_"+val).checked = true;
}else{
uncheckAll();
console.log('choose only between 1 or 2');
}
}
function uncheckAll(){
let ele = document.getElementsByName("RdioSelect");
for(var i=0;i<ele.length;i++){
ele[i].checked = false;
}
}
<input id="Rdio_1" name="RdioSelect" type="radio" class="FirstCheck"
value="1" onchange="RadioValInsert ()"/>
<input id="Rdio_2" name="RdioSelect" type="radio" class="FirstCheck"
value="2" onchange="RadioValInsert ()" />
<input type="text" id="DatafromRadio" name="DatafromRadio">

Try this example where radio selection and textbox value changes as per selection/input
document.addEventListener('DOMContentLoaded', function(dce) {
var radios = document.querySelectorAll('[name="RdioSelect"]');
var textbx = document.querySelector('[name="DatafromRadio"]');
radios.forEach(function(r) {
r.addEventListener('click', function(e) {
textbx.value = this.value;
});
});
textbx.addEventListener('input', function(e) {
radios.forEach(function(r) {
r.checked = (r.value === textbx.value);
});
});
var fillTxt = function(txt) {
textbx.value = txt;
textbx.dispatchEvent(new Event('input')); //<-- trigger event
};
fillTxt('2'); //<--- update text box
});
<input id="Rdio_1" name="RdioSelect" type="radio" value="1" />
<input id="Rdio_2" name="RdioSelect" type="radio" value="2" />
<input type="text" id="DatafromRadio" name="DatafromRadio" />
this works only if data is input physically in the text box - in my case the data is retrieved via a function and it populates the text box
In that, just trigger event on textbox

checkbox onclick wont change checked via jscript

I have 3 checkboxes, i wish to be able to click the box and it tick on/off and via jscript change the value of the input for posting to state weather item is accepted or not on another page. However i have logical script but it wont work, theres no errors but the checkboxes wont click on/off they just click on and thats it.. and the value wont change either i dont understand why.
Could somebody look at this short code and tell me why.
Thank you.
<input type="checkbox" id="paypal" name="paypal1" value=" " onclick='chbxpp();' >
</input>
<label for="paypal" class="checkboxes" >Show PayPal Accepted</label>
<br>
<input type="checkbox" id="facebook" name="facebook" value=" " onclick='chbxfb(this);' >
</input>
<label for="facebook" class="checkboxes" >Show FaceBook Contact Details</label>
<br>
<input type="checkbox" id="twitter" name="twitter" value=" " onclick='chbxtw(this);' >
</input>
<label for="twitter" class="checkboxes" >Show Twitter Contact Details</label>
function chbxpp()
{
if(document.getElementById('paypal').checked === true) {
document.getElementById('paypal').checked = false;
document.getElementById('paypal').value='no';
var vv=document.getElementById('paypal').value;
console.log(vv);
}
if (document.getElementById('paypal').checked === false) {
document.getElementById('paypal').checked = true;
document.getElementById('paypal').value='yes';
var vv=document.getElementById('paypal').value;
console.log(vv);
}
}
function chbxfb(objfb)
{
var that = objfb;
(objfb);
if(document.getElementById(that.id).checked === true) {
document.getElementById(that.id).checked = false;
document.getElementById(that.id).value='no';
var vv=document.getElementById(that.id).value;
console.log(vv);
}
if (document.getElementById(that.id).checked === false) {
document.getElementById(that.id).checked = true;
document.getElementById(that.id).value='yes';
var vv=document.getElementById(that.id).value;
console.log(vv);
}
}
function chbxtw(objtw)
{
var that = objtw;
(objtw);
if(document.getElementById(that.id).checked === true) {
document.getElementById(that.id).checked = false;
document.getElementById(that.id).value='no';
var vv=document.getElementById(that.id).value;
console.log(vv);
}
if (document.getElementById(that.id).checked === false) {
document.getElementById(that.id).checked = true;
document.getElementById(that.id).value='yes';
var vv=document.getElementById(that.id).value;
console.log(vv);
}
}
The objpp was my attempt at another method but just does the same thing...
p.s if i just didnt use jscript and just had the html, would the value not be valid if the checkbox was not clicked or would the value still be sent...
iv just fond this..
How to change the value of a check box onClick using JQuery?
states that the value wont be sent if the box is unchecked... But then how do i know after post what has been clicked.... will i receieve a not isset($_POST['paypal']) or an empty($_POST['paypal'])

I imagine your checkboxes begin with no check inside them or .checked === false, but when you call your function chbxpp(), it looks to see if your .checked property === true and if so it sets it back to false. The click event already changes the checkbox's .checked property for you, no need to do it in your code.
//If the checkbox is checked, set it to not checked...???
//But the problem is, the click event just set the .checked property to true
//so setting it back to false makes it like it never happened.
if(document.getElementById('paypal').checked === true) {
//document.getElementById('paypal').checked = false; //This part is a no-no
document.getElementById('paypal').value='yes';
}else{
document.getElementById('paypal').value='no';
}

Adding to Ryan Wilson's answer, set your cbx's initial value to false. (Also check the format of the cbx - the closing tag.)
<input type="checkbox" id="paypal" name="paypal1" value="false" onchange="chbxpp();" />
function chbxpp() {
// the cbx starts false. when it is clicked for the first time it
// becomes true.
if (document.getElementById('paypal').checked) {
// you don't need this.
//document.getElementById('paypal').checked = true;
document.getElementById('paypal').value = 'yes';
var vv = document.getElementById('paypal').value;
console.log(vv);
} else {
// you also don't need this.
//document.getElementById('paypal').checked = false;
document.getElementById('paypal').value = 'no';
var vv = document.getElementById('paypal').value;
console.log(vv);
}
}

Validating a checkbox after already validating other sections of a form [duplicate]

I have a form with multiple checkboxes and I want to use JavaScript to make sure at least one is checked. This is what I have right now but no matter what is chosen an alert pops up.
JS (wrong)
function valthis(){
if (document.FC.c1.checked) {
alert ("thank you for checking a checkbox")
} else {
alert ("please check a checkbox")
}
}
HTML
<p>Please select at least one Checkbox</p>
<br>
<br>
<form name = "FC">
<input type = "checkbox" name = "c1" value = "c1"/> C1
<br>
<input type = "checkbox" name = "c1" value = "c2"/> C2
<br>
<input type = "checkbox" name = "c1" value = "c3"/> C3
<br>
<input type = "checkbox" name = "c1" value = "c4"/> C4
<br>
</form>
<br>
<br>
<input type = "button" value = "Edit and Report" onClick = "valthisform();">
So what I ended up doing in JS was this:
function valthisform(){
var chkd = document.FC.c1.checked || document.FC.c2.checked||document.FC.c3.checked|| document.FC.c4.checked
if (chkd == true){
} else {
alert ("please check a checkbox")
}
}
I decided to drop the "Thank you" part to fit in with the rest of the assignment. Thank you so much, every ones advice really helped out.

You should avoid having two checkboxes with the same name if you plan to reference them like document.FC.c1. If you have multiple checkboxes named c1 how will the browser know which you are referring to?
Here's a non-jQuery solution to check if any checkboxes on the page are checked.
var checkboxes = document.querySelectorAll('input[type="checkbox"]');
var checkedOne = Array.prototype.slice.call(checkboxes).some(x => x.checked);
You need the Array.prototype.slice.call part to convert the NodeList returned by document.querySelectorAll into an array that you can call some on.

This should work:
function valthisform()
{
var checkboxs=document.getElementsByName("c1");
var okay=false;
for(var i=0,l=checkboxs.length;i<l;i++)
{
if(checkboxs[i].checked)
{
okay=true;
break;
}
}
if(okay)alert("Thank you for checking a checkbox");
else alert("Please check a checkbox");
}
If you have a question about the code, just comment.
I use l=checkboxs.length to improve the performance. See http://www.erichynds.com/javascript/javascript-loop-performance-caching-the-length-property-of-an-array/

I would opt for a more functional approach. Since ES6 we have been given such nice tools to solve our problems, so why not use them.
Let's begin with giving the checkboxes a class so we can round them up very nicely.
I prefer to use a class instead of input[type="checkbox"] because now the solution is more generic and can be used also when you have more groups of checkboxes in your document.
HTML
<input type="checkbox" class="checkbox" value=ck1 /> ck1<br />
<input type="checkbox" class="checkbox" value=ck2 /> ck2<br />
JavaScript
function atLeastOneCheckboxIsChecked(){
const checkboxes = Array.from(document.querySelectorAll(".checkbox"));
return checkboxes.reduce((acc, curr) => acc || curr.checked, false);
}
When called, the function will return false if no checkbox has been checked and true if one or both is.
It works as follows, the reducer function has two arguments, the accumulator (acc) and the current value (curr). For every iteration over the array, the reducer will return true if either the accumulator or the current value is true.
the return value of the previous iteration is the accumulator of the current iteration, therefore, if it ever is true, it will stay true until the end.

Check this.
You can't access form inputs via their name. Use document.getElements methods instead.

Vanilla JS:
var checkboxes = document.getElementsByClassName('activityCheckbox'); // puts all your checkboxes in a variable
function activitiesReset() {
var checkboxesChecked = function () { // if a checkbox is checked, function ends and returns true. If all checkboxes have been iterated through (which means they are all unchecked), returns false.
for (var i = 0; i < checkboxes.length; i++) {
if (checkboxes[i].checked) {
return true;
}
}
return false;
}
error[2].style.display = 'none'; // an array item specific to my project - it's a red label which says 'Please check a checkbox!'. Here its display is set to none, so the initial non-error label is visible instead.
if (submitCounter > 0 && checkboxesChecked() === false) { // if a form submit has been attempted, and if all checkboxes are unchecked
error[2].style.display = 'block'; // red error label is now visible.
}
}
for (var i=0; i<checkboxes.length; i++) { // whenever a checkbox is checked or unchecked, activitiesReset runs.
checkboxes[i].addEventListener('change', activitiesReset);
}
Explanation:
Once a form submit has been attempted, this will update your checkbox section's label to notify the user to check a checkbox if he/she hasn't yet. If no checkboxes are checked, a hidden 'error' label is revealed prompting the user to 'Please check a checkbox!'. If the user checks at least one checkbox, the red label is instantaneously hidden again, revealing the original label. If the user again un-checks all checkboxes, the red label returns in real-time. This is made possible by JavaScript's onchange event (written as .addEventListener('change', function(){});

You can check that atleast one checkbox is checked or not using this simple code. You can also drop your message.
Reference Link
<label class="control-label col-sm-4">Check Box 2</label>
<input type="checkbox" name="checkbox2" id="checkbox2" value=ck1 /> ck1<br />
<input type="checkbox" name="checkbox2" id="checkbox2" value=ck2 /> ck2<br />
<script>
function checkFormData() {
if (!$('input[name=checkbox2]:checked').length > 0) {
document.getElementById("errMessage").innerHTML = "Check Box 2 can not be null";
return false;
}
alert("Success");
return true;
}
</script>

< script type = "text/javascript" src = "js/jquery-1.6.4.min.js" > < / script >
< script type = "text/javascript" >
function checkSelectedAtleastOne(clsName) {
if (selectedValue == "select")
return false;
var i = 0;
$("." + clsName).each(function () {
if ($(this).is(':checked')) {
i = 1;
}
});
if (i == 0) {
alert("Please select atleast one users");
return false;
} else if (i == 1) {
return true;
}
return true;
}
$(document).ready(function () {
$('#chkSearchAll').click(function () {
var checked = $(this).is(':checked');
$('.clsChkSearch').each(function () {
var checkBox = $(this);
if (checked) {
checkBox.prop('checked', true);
} else {
checkBox.prop('checked', false);
}
});
});
//for select and deselect 'select all' check box when clicking individual check boxes
$(".clsChkSearch").click(function () {
var i = 0;
$(".clsChkSearch").each(function () {
if ($(this).is(':checked')) {}
else {
i = 1; //unchecked
}
});
if (i == 0) {
$("#chkSearchAll").attr("checked", true)
} else if (i == 1) {
$("#chkSearchAll").attr("checked", false)
}
});
});
< / script >

Prevent user from deselecting last checked checkbox.
jQuery (original answer).
$('input[type="checkbox"][name="chkBx"]').on('change',function(){
var getArrVal = $('input[type="checkbox"][name="chkBx"]:checked').map(function(){
return this.value;
}).toArray();
if(getArrVal.length){
//execute the code
$('#msg').html(getArrVal.toString());
} else {
$(this).prop("checked",true);
$('#msg').html("At least one value must be checked!");
return false;
}
});
UPDATED ANSWER 2019-05-31
Plain JS
let i,
el = document.querySelectorAll('input[type="checkbox"][name="chkBx"]'),
msg = document.getElementById('msg'),
onChange = function(ev){
ev.preventDefault();
let _this = this,
arrVal = Array.prototype.slice.call(
document.querySelectorAll('input[type="checkbox"][name="chkBx"]:checked'))
.map(function(cur){return cur.value});
if(arrVal.length){
msg.innerHTML = JSON.stringify(arrVal);
} else {
_this.checked=true;
msg.innerHTML = "At least one value must be checked!";
}
};
for(i=el.length;i--;){el[i].addEventListener('change',onChange,false);}
<label><input type="checkbox" name="chkBx" value="value1" checked> Value1</label>
<label><input type="checkbox" name="chkBx" value="value2"> Value2</label>
<label><input type="checkbox" name="chkBx" value="value3"> Value3</label>
<div id="msg"></div>

$('input:checkbox[type=checkbox]').on('change',function(){
if($('input:checkbox[type=checkbox]').is(":checked") == true){
$('.removedisable').removeClass('disabled');
}else{
$('.removedisable').addClass('disabled');
});

if(($("#checkboxid1").is(":checked")) || ($("#checkboxid2").is(":checked"))
|| ($("#checkboxid3").is(":checked"))) {
//Your Code here
}
You can use this code to verify that checkbox is checked at least one.
Thanks!!

How do I properly validate the form using input radios?

I have a problem with validating the form in function validate() method. This line of code:
if(radios[i].value == "yes" && radios[i].checked == true) //DEBUG INFO: skips this step to else.
is being skipped because one or both of the conditions are false, but I'm not sure which one and as well as if the condition is proper to execute. I was thinking that radios[i].value == "yes" will correspond to the value attribute of that input radio button (In other words, the correct answer regarding that question).
When the submit button is clicked, I simply want javascript to tell me whether it's correct or not and to check if the radio button is checked.
Problem: I checked in the radio button, when submit button is clicked the alert for Please make sure you answer every question pops up 3 times and after that displays that I have the correct answer.
Here's the full code:
JavaScript:
// called when "Take Quiz" button is clicked
function takeQuiz()
{
// hide the intro
document.getElementById('intro').style.display = 'none';
// display the quiz
document.getElementById('message').style.overflow = 'auto';
document.getElementById('quiz').style.visibility = 'visible';
document.getElementById('gl_banner').style.display = 'block';
document.getElementById('gl_banner').style.visibility = 'visible';
}
//document.getElementById('submit').onclick = validateQuiz; //calls the function "validateQuiz" when submit button is clicked
// check for validation in the quiz
function validateQuiz()
{
var radios; // access elements by object name (DOM)
var i; // int variable
var right; // boolean variable to determine correct answer
radios = document.getElementById('question1').getElementsByTagName('input');
/*radios = document.getElementById('question2').getElementsByTagName('input');
radios = document.getElementById('question3').getElementsByTagName('input');
radios = document.getElementById('question4').getElementsByTagName('input');
radios = document.getElementById('question5').getElementsByTagName('input');*/
right = true;
// loop to check each radio button for validation
for(i = 0; i < radios.length; i++)
{
if(radios[i].value == "yes" && radios[i].checked == true) //DEBUG INFO: skips this step to else.
{
right = true;
}
else if(radios[i].checked == false)
{
right = false;
alert("Please check to make sure you have answered every question.");
}
}
if(right)
{
alert("You have answered correctly!");
}
else
{
alert("Wrong answer");
}
}
HTML Code:
<div id="message" style="overflow:hidden;"><div id="intro">Why not go ahead and take the quiz to test your knowledge based on what you've learned in Smartphone Photography.
There are only 5 questions surrounding the content of this site.
<br/>
<button id="takeQuiz" type="button" name="name" onclick="takeQuiz()" style="cursor:pointer;">Take Quiz!</button></div>
<div id="gl_banner" style="display:none; visibility:hidden;">Good Luck! :)</div>
<form id="quiz" action="#" method="post" style="visibility:hidden;" autocomplete="off">
<!--QUIZ-->
<h3>1. How many percent of modern camera phones use CMOS?</h3>
<div id="question1">
<input type="radio" name="question-1-answers" id="question-1-answers-A" value="A" />
<label for="question-1-answers-A">A) 20%</label>
<br/>
<input type="radio" name="question-1-answers" id="question-1-answers-B" value="B" />
<label for="question-1-answers-B">B) 80%</label>
<br/>
<input type="radio" name="question-1-answers" id="question-1-answers-C" value="C" />
<label for="question-1-answers-C">C) 50%</label>
<br/>
<input type="radio" name="question-1-answers" id="question-1-answers-D" value="yes" />
<label for="question-1-answers-D">D) 90%</label>
</div>

**Edited for a pure javascript solution.
I got the function to get the select value from this post.
I don't think you need to do a loop here, as you only actually need to check one value- the value of the checked radio.
At the moment your looping through all the radios, so you'll always get three wrong answers.
**Edited again to fix some code errors. I have tested the following, it is working for me.
function getRadioValue(name) {
var group = document.getElementsByName(name);
for (var i=0;i<group.length;i++) {
if (group[i].checked) {
return group[i].value;
}
}
return '';
}
document.getElementById('submit').onclick = validateQuiz; //calls the function "validateQuiz" when submit button is clicked
// check for validation in the quiz
function validateQuiz(){
right = true;
radio = getRadioValue("question-1-answers");
if(!radio.length) {
right = false;
alert("Please check to make sure you have answered every question.");
return;
}
if(radio == 'yes')
{
alert("You have answered correctly!");
}
else {
right = false;
alert("Wrong answer");
}
}

How to reset/uncheck radio button onclick event?

I have 2 radio button with 2 group.
The structure is like this
Main Radio 1
Main Radio 2
Under Main Radio 2, there's two more sub radio button.
Main Radio 1
Main Radio 2
Sub Radio 1
Sub Radio 2
What am I doing is, in default stage, it will only show Main Radio 1 and Main Radio 2 button. When choose Main Radio 2, two sub radio button of Main Radio 2 appear.
When choose back to Main Radio 1, it will hide the list of Main Radio 2.
The one that I want to achieve is,
When click Main Radio 1, the selection that I made for Sub Radio 1 or Sub Radio 2, want to be uncheck / reset too.
I tried with this javascript, but no success.
document.getElementById("subradiobuttons").reset();
Please kindly help me the solutions. Thank you.
With Regards,

I think the best approach for a simple task like this does not needs a full JavaScript library like jQuery.
document.getElementById("main2").addEventListener("click", function()
{
document.getElementById("subCheckButtons").style.opacity = 1;
}, false);
document.getElementById("main1").addEventListener("click", function()
{
document.getElementById("subCheckButtons").style.opacity = 0;
document.getElementById("sub1").checked = false;
document.getElementById("sub2").checked = false;
}, false);
<input type="radio" id="main1" name="main" />
<input type="radio" id="main2" name="main" />
<div id="subCheckButtons" style="opacity:0;">
<input type="radio" id="sub1" name="sub" class="subCheck" />
<input type="radio" id="sub2" name="sub" class="subCheck" />
</div>
Or see the fiddle.

Here is another approach that will reset all inputs to their default position if someone clicks on "Main Radio 1."
//Clear all inputs.
function clearInputs(form) {
"use strict";
//Gather all inputs within selected form.
const inputs = form.querySelectorAll("input");
//Clear the inputs.
inputs.forEach(function (input) {
if (input.hasAttribute("checked") === true) {
input.checked = true;
} else {
input.checked = false;
}
});
}
//Monitor "Main Radio 1" for clicks.
function monitorMainRadio1() {
"use strict";
const form = document.getElementById("form");
const mainRadio1 = document.getElementById("main-radio1");
mainRadio1.addEventListener("click", function () {
clearInputs(form);
});
}
//Invoke the monitorMainRadio1 function.
monitorMainRadio1();

Not tested this but...
<input type="radio" onclick="document.getElementById("subradiobuttons").Checked = false;" />
Or you could call a Javascript function to do a bit more work/logic
This page has what you need

It is much, much quicker to do this with jQuery than JavaScript. I recommend you do something like this;
Give the radio boxes something like this
<input type="radio" name="main1">
<input type="radio" name="main2">
<input type="radio" name="sub">
<input type="radio" name="sub">​
Then with jQuery you can do this
$('input[name=main1]').on('click', function() {
$('input[name=sub]').attr('checked', false);
});
I've assumed here that you've figured out a way to hide the sub radio buttons. ​
See a fiddle of this here
Also, make sure that you include jQuery at the top of the <script></script> tags containing this code.
script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"

Reset the radiobutton or RadiobuttonList in the form:
private void ResetFormControlValues(Control parent)
{
foreach (Control c in parent.Controls)
{
if (c.Controls.Count > 0)
{
ResetFormControlValues(c);
}
else
{
switch ((c.GetType().ToString()))
{
case "System.Web.UI.WebControls.TextBox":
((TextBox)c).Text = "";
break;
case "System.Web.UI.WebControls.CheckBox":
((CheckBox)c).Checked = false;
break;
case "System.Web.UI.WebControls.RadioButton":
((RadioButton)c).Checked = false;
break;
case "System.Web.UI.WebControls.DropDownList":
((DropDownList)c).SelectedIndex = 0;
break;
}
}
}
}