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);
}
}

How to check checkbox checked or not using javascript?

How to check checkbox checked or not using javascript ?
I have a lot of checkbox (dynamic data) . I want to know how can i check when checked chekcbox >= '1' using javascript ?
<input type="checkbox" id="1" name="test[]" onclick="test_fn()"/>
<input type="checkbox" id="2" name="test[]" onclick="test_fn()"/>
<input type="checkbox" id="3" name="test[]" onclick="test_fn()"/>
<input type="checkbox" id="4" name="test[]" onclick="test_fn()"/>
<script>
function test_fn() {
// check it's have checked checkbox or not ? //
}
</script>

Try to pass this in your inline handler,
<input type="checkbox" id="1" name="test[]" onclick="test_fn(this)"/>
And use this.checked to find out whether it is checked or not,
function test_fn(elem) {
alert(elem.checked);
}
DEMO
To check, if the the checked check box greater than or equal to 1, then just do
function test_fn(elem) {
if (document.querySelectorAll("input[name='test[]']:checked").length >= 1) {
alert("yes it is greater than or equal to 1")
}
}
DEMO

function test_fn()
{
if (this.checked) return true;
else return false;
}
Edit:
this reference won't work in this case, thanks to #RajaprabhuAravindasamy for pointing this out, read the comments or check this SO question for more information.
You need to pass a reference explicitly to the checkbox element:
function test_fn (el)
{
if (el.checked) return true;
else return false;
}
As for how to know if checked boxes count is more than one you can simply use a global variable to keep a track of the count like this:
var count = 0;
function test_fn (el)
{
el.checked ? count++ : count--;
return count > 1;
// if (count > 1) alert ("count is more than 1");
}
Demo

Add another condition to Show/Hide Divs

I have the follow script on a form.
jQuery(document).ready(function($) {
$('#bizloctype').on('change',function() {
$('#packages div').show().not(".package-" + this.value).hide();
});
});
</script>
Basically, depending on the value of the select box #bizloctype (value="1","2","3" or "4") the corresponding div shows and the rest are hidden (div class="package-1","package-2","package-3", or "package-4"). Works perfectly.
BUT, I need to add an additional condition. I need the text box #annualsales to be another condition determining which div shows (if the value is less than 35000 then it should show package-1 only, and no other packages.
I think the below script works fine when independent of the other script but I need to find out how to marry them.
<script>
$("#annualsales").change(function(){
$(".package-1,.package-2,.package-3,.package-4").hide();
var myValue = $(this).val();
if(myValue <= 35000){
$(".package-1").show();
}
else
{
$(".package-2").show();
}
});
</script>
Help please?

I would remove the logic from the anonymous functions and do something like this:
// handle display
function displayPackage( fieldID ) {
var packageType = getPackageType(fieldID);
$('#packages div').show().not(".package-" + packageType).hide();
}
// getting the correct value (1,2,3 or 4)
function getPackageType( fieldID ) {
// default displayed type
var v = 1;
switch(fieldID) {
case 'bizloctype':
// first check it annualsales is 1
v = (getPackageType('annualsales') == 1) ?
1 : $('#' + fieldID).val();
break;
case 'annualsales':
v = (parseInt($('#' + fieldID).val(),10) <= 35000) ? 1 : 2;
break;
}
return v;
}
jQuery(document).ready(function($) {
$('#bizloctype,#annualsales').on('change',function() {
displayPackage($(this).attr('id'));
});
});

If I understand your question properly, try this code out. It first adds an onChange listener to #annualsales which is the code you originally had. Then, for the onChange listener for #bizloctype, it simply checks the value of #annualsales before displaying the other packages.
jQuery(document).ready(function($) {
// Check value of #annualsales on change
$("#annualsales").change(function(){
$(".package-1,.package-2,.package-3,.package-4").hide();
var myValue = $(this).val();
if(myValue <= 35000){
$(".package-1").show();
}
// Only show other packages if value is > 35000
$('#bizloctype').on('change',function() {
$(".package-1,.package-2,.package-3,.package-4").hide();
if ($('#annualsales').val() <= 35000) {
$(".package-1").show();
} else {
$('#packages div').show().not(".package-" + this.value).hide();
}
});
});

Since you already use JQuery you can use the data() function to create a simple but dynamic condition system. For example, you could annotate each element with the required conditions and then attach change listeners to other elements to make the condition active or inactive for the elements.
For example, with this HTML:
<div id="conditions">
Condition 1: <input type="checkbox" id="check1" /> <= check this<br/>
Condition 2: <input type="checkbox" id="check2" /><br/>
Condition 3: <input type="text" id="value1" /> <= introduce 1001 or greater<br/>
Condition 4: <input type="text" id="value2" /><br/>
</div>
<p id="thing" data-show-conditions="check1 value1-gt-1000"
style="display: none;">
The thing to show.
</p>
And this Javascript:
function setShowCondition(el, condition, active) {
var conditions = $(el).data('conditions') || {};
conditions[condition] = active;
$(el).data('conditions', conditions);
var required = ($(el).data('show-conditions') || "").split(" ");
var visible = required.every(function (c) {
return conditions[c];
});
if (visible) {
$(el).show();
} else {
$(el).hide();
}
}
$("#conditions input[type='checkbox'").change(function () {
setShowCondition('#thing',
$(this).attr('id'),
$(this).is(':checked'));
});
$("#value1").change(function () {
var number = parseInt($(this).val());
setShowCondition('#thing', 'value1-gt-1000', number > 1000);
});
You can maintain conditions easily without having to nest and combine several if statements.
I've prepared a sample to show this in https://jsfiddle.net/2L5brd80/.

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!!

Validating a single radio button is not working in available javascript validation script

I have randomly generated radio button series like
<input type="radio" name="creatorusers" value="1">
<input type="radio" name="creatorusers" value="1">
<input type="radio" name="creatorusers" value="1">
<input type="radio" name="creatorusers" value="1">
.....so on
But I get only ONE radio button and execute the javascript validation given for it to chk whether the radio button is selected or not, then it doesnt work
Ples help me out in resolving this.
mycreator = -1;
for (i=frm.creatorusers.length-1; i > -1; i--) {
if (frm.creatorusers[i].checked) {
mycreator = i; i = -1;
}
}
if (mycreator == -1) {
alert("You must select a Creator User!");
return false;
}

Always (!) use the var keyword. Otherwise your variables will be in the global scope (yes, even those in function bodies), which can make for some bugs that are hard to track down.
As #Felix pointed out, creatorusers will only be an array if there is more than one element with that name in the form. You can create a single-element array when necessary to work around that.
Here is an abstracted function that can validate an arbitrary checkbox list.
function ensureChecked(checkboxes, error) {
if (checkboxes) {
var cbx = (checkboxes.length > 0) ? checkboxes : [checkboxes];
for (var i=0; i<cbx.length; i++) {
if (cbx[i].checked) {
return true;
}
}
alert(error);
}
return false;
}
call as
ensureChecked(frm.creatorusers, "You must select a Creator User!");

Ah now I got. If you only have one radio button, then frm.creatorusers is not an array. Just skip it:
var mycreator = -1;
var checked = false;
if(typeof frm.creatorusers.length === 'number') {
for (var i=frm.creatorusers.length; i--; ) {
if (frm.creatorusers[i].checked) {
mycreator = i;
checked = true;
break;
}
}
}
else if(frm.creatorusers.checked){
mycreator = //? what here?
checked = true;
}
if(!checked) {
alert("You must select a Creator User!");
return false;
}
If mycreator was just for checking whether a button was selected or not, you can completely remove it from the code above.
Some further notes to your code:
Always declare variables with var, otherwise they will be global.
Use break to end a loop.
Maybe it is just because of copy and paste, but having a lot of radio buttons with the same value does not make much sense.

You can do something like this:
function validate(frm){
var isChecked = false;
for (var i=0; i<frm.elements.length; i++)
{
if (frm.elements[i].type === 'radio'){
if (frm.elements[i].checked === true){
isChecked = true;
break;
}
}
}
if (isChecked === true){
return true;
}
else{
alert('You should select an option first !');
}
}
Now you should call above function on onsubmit event of the form:
<form onsubmit="return validate(this);">
Now the validate function will make sure that at least one radio button is checked otherwise it won't submit.

this should do it
function isRadioSelected(btn) {
if(typeof btn.length === 'number') {
for(var i=0;i<btn.length;i++)
if(btn[i].checked) return true
}else{
if(btn.checked) return true
}
return false
}

You could try something like this instead:
<html>
<head>
<script type="text/javascript">
function confirmsubmit() {
var btn = document.formname.buttonname
if (btn.checked == false)
{
window.alert("You did not click the button.");
btn.focus();
return false;
}
return true;
}
</script>
</head>
<body>
<form method="post" action="mailto:youremail#yourdomain.com"
name="formname" onsubmit="return confirmsubmit();">
click here: <input type="radio" name="buttonname"><br />
<p><input type="submit" value="Submit" name="submit"></p>
</form>
</body>
</html>