Develop Reference

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);
}
}

Validate checkbox with AngularJs

Again i'm having trouble with checkboxes. I'm getting info from an API and showing like checkbox. The problem comes when i'm triying to add a validation. This is a part of my code:
(function() {
'use strict';
var fact = {
templateUrl: './app/components/fact.components.html',
controller: factCtrl
};
angular.module('fApp').component('odcFacturas', fact);
factCtrl.$inject = ["$scope", "couponApi"];
function factCtrl($scope, couponApi) {
var vm = this;
vm.clientOrder = null;
vm.all = false;
vm.sendData = function() {
vm.apiData = couponApi.get({
idOrder: vm.idOrder
}).$promise.then(function(data) {
for (var i = 0; i < data.Response.length; i++) {
data.Response[i].Select = vm.all;
}
vm.coupons = data.Response;
vm.combo = data.Response.length > 0;
});
}
Here i call the info, and the next part of my code check all the checkboxes:
vm.selectAll = function() {
for (var i = 0; i < vm.coupons.length; i++) {
vm.coupons[i].Select = vm.all;
}
if (vm.all == 0) {
alert("Select at least one coupon");
}
}
How can I trigger three validations with a submit button? I mean: what I want to do is validate three cases:
if the checkbox "select all checkboxes" is checked, submit
if there's no selected checkboxes, show the alert message
if there's at least one checkbox (or 'n' checkboxes) selected,
submit
On the HTML view i have this:
<div class ="container-fluid">
<div class="row">
<div class="col-md-6">
<div class="cbx input-group">
<div class="checkbox" name="imtesting" ng-show="$ctrl.coupons.length > 0">
<label><input type="checkbox"
ng-show="$ctrl.coupons.length > 0"
name="allCoupons"
ng-model="$ctrl.all"
ng-click="$ctrl.selectAll()"/>Select all coupons</label>
<ul>
<li ng-repeat="c in $ctrl.coupons">
<input type="checkbox"
name="couponBox"
ng-model="c.Select"
ng-click="$ctrl.result()"
required/>{{c.CodeCoupon}}
<br>
</li>
</ul>
<label class="label label-danger" ng-show="submitted == true && !ctrl.newTest()">Select at least one coupon</label>
</div>
</div>
</div>
</div>
Hope you can help me.
Thanx in advance.

You can use the Select property from each coupon object like
vm.canSubmit = function() {
for(var i = 0; i< vm.coupons.length; i++)
{
if (vm.coupons[i].Select) {
return true;
}
}
return false;
}

Redo the way you are handling your selectsAll function. When you are using angular there is a thing called scope.$apply that is actually running which tells the dom to update if the object or properties have changed. Sometimes if you use for loops the way you are using them it wont register a change.
Try this and it should work:
vm.selectAll = function()
{
vm.all = !vm.all;
vm.coupons.forEach(function(o){
o.Select = vm.all;
})
}
vm.submit = function(){
var checked = 0;
vm.coupons.forEach(function(o){
if(o.Select === true)
checked +=1;
})
if(vm.all || checked > 0){
//submit here
}
else if(checked === 0){
//error
}
}
This will work both ways. If checked it will check all and if unchecked it will uncheck all. That validation will work for all three scenarios.

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!!

making the checkbox to display div

here am trying to display divs ClinicFieldSet and HospitalFieldset by selecting the given text boxes. If both are selected, both ClinicFieldset and HospitalFieldset should display and if one of the check box is selected it should show which div is selected.
The problem with my script is, when one of the checkboxes are clicked, both checkboxes are getting selected and it is not posible to uncheck them also. So please suggest me an idea to fix this problem :(
I used Javascript onClick in both checkboxes to apply on both of them.
<script type="text/javascript>
var clinic = document.getElementById('clinic');
var visit = document.getElementById('visit');
if((clinic.checked = true) && (visit.checked = true) )
{
document.getElementById('ClinicFieldSet').style.display='block';
document.getElementById('HospitalFieldSet').style.display='block';
}
else if((clinic.checked = true) && (visit.checked = false))
{
document.getElementById('ClinicFieldSet').style.display='block';
document.getElementById('HospitalFieldSet').style.display='none';
}
else if((clinic.checked = false) && (visit.checked = true))
{
document.getElementById('ClinicFieldSet').style.display='none';
document.getElementById('HospitalFieldSet').style.display='block';
}
else
{
document.getElementById('ClinicFieldSet').style.display='none';
document.getElementById('HospitalFieldSet').style.display='none';
}
HTML
<input type="checkbox" name="type" id="clinic" onClick="dispp();" >Clinic Practice
<input type="checkbox" name="type" id="visit" onClick="dispp();" >Visiting Hospital

In your if statement use the == equality operator.
The single = is used to assign a value, not test its equality.

May I suggest a revised approach (not using in-line click-handlers) with a slightly amended html, just to make the JavaScript somewhat more simple:
HTML:
<input type="checkbox" name="type" id="clinic" /><label for="clinic">Clinic Practice</label>
<input type="checkbox" name="type" id="hospital" /><label for="hospital">Visiting Hospital</label>
<div id="clinicInfo">
<h2>Clinic information</h2>
</div>
<div id="hospitalInfo">
<h2>Hospital information</h2>
</div>
JavaScript:
document.getElementById('hospitalInfo').style.display = 'none';
document.getElementById('clinicInfo').style.display = 'none';
var inputs = document.getElementsByTagName('input');
function dispp() {
if (this.checked) {
document.getElementById(this.id + 'Info').style.display = 'block';
}
else {
document.getElementById(this.id + 'Info').style.display = 'none';
}
}
for (i = 0; i < inputs.length; i++) {
if (inputs[i].type.toLowerCase() == 'checkbox') {
inputs[i].onchange = dispp;
}
}
JS Fiddle demo.

Try this
if(clinic.checked == true)
{
document.getElementById('ClinicFieldSet').style.display='block';
}
else
{
document.getElementById('ClinicFieldSet').style.display='none';
}
if(visit.checked == true)
{
document.getElementById('HospitalFieldSet').style.display='block';
}
else
{
document.getElementById('HospitalFieldSet').style.display='none';
}

var form=document.forms.add
form.elements.check.addEventListener('change',function(e) {
e.preventDefault()
var check=document.querySelector('.check')
if(check.checked=true)
{
document.querySelector('.inside').style.display='block'
}
else{
document.querySelector('.inside').style.display='none'
}
})

too see if checkboxes have been checked javascript

Hallo
How would I go about in checking whether checkBox has been checked in javascript?
I C# it is simple enough
int selected = 0;
for (int loop = 0; loop < chkMeal.CheckedItems.Count; loop++)
{
selected++;
}
if (selected > 1)
{
MessageBox.Show("only one meal allowed", "Halt", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
How could I do a simlar thing with javascript?
kind regards
Arian

For instance, if you give your checkboxes a class you can do something like this:
var myboxes = document.getElementsByClassName('myboxes');
for (var i=0; i<myboxes.length;i++) {
if (myboxes[i].checked) {
alert('Box number '+i+' is checked!');
}
}

Simply put, give your form a unique id attribute. Then, traverse HTMLFormElement.elements and check against HTMLInputElement.checked for a truthy value.
HTML:
<form id="foo" method="post" action="./">
<input type="checkbox" name="check_a" value="foo" />
<input type="checkbox" name="check_b" value="bar" />
<input type="checkbox" name="check_c" value="baz" checked />
</form>
JS:
var foo = document.getElementById("foo"), i = 0, el;
for(i;i<foo.elements.length;i++)
{
el = foo.elements[i];
if(el.nodeType === 1 && el.tagName === "INPUT" && el.type === "checkbox")
{
//element node, is an input element, is a checkbox
if(el.checked)
{
//checkbox is checked
}
}
el = null;
}
Bonus reference:
HTMLFormElement (via DOM Level 2)
HTMLInputElement (via DOM Level 2)

Using a little bit of jQuery:
$(function() {
$('form').submit( function() {
if ($('[name="chkMeal"]:checked').length > 1) {
// show an error
return false; // cancel submit
}
});
});