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Hi All, Hope all is well well. I have a coding question I cant seem to figure out. I have a form in HTML5 which has columns that I want to sum and show in a totals box. The totals are summed when a button that calls the sum() function when clicked. From the code below I'm just trying to sum two boxes which represent a value for each hour total. My problem is that when I click on the button with only a value in the first box, then i get a NaN in the results box...no matter how many times i click it...but when i enter a value in the second box the sum is completed and the correct total is displayed. Could someone explain please why this only works with 2 values and not just 1....hope this is clear. Thanks to all who try
regards
<pre><script type="text/javascript" ></script>
<script type="text/javascript">
function sum() {
var result= 0;
var txtFirstNo = document.getElementById('Text1').value;
var txtSecondNo = document.getElementById('Text6').value;
if (!isNaN(txtFirstNo)){
result = parseInt(txtFirstNo);
document.getElementById('Tar').value = parseInt(result);
}
if (!isNaN(txtSecondNo)){
result = parseInt(txtFirstNo) + parseInt(txtSecondNo);
document.getElementById('Tar').value = result;
}
if (!isNaN(result)) {
document.getElementById('Tar').value = result;
}
}
</script>
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All you have to do is debug your code and you'll figure it out. Note, isNaN('') returns false because '' gets converted to a number first (0).
But all you have to do is debug. Very easy.
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NaN means "Not a Number" and that's telling you something of the problem.
What is the value of what's in the empty box? If you parseInt() something that is in possibly not a number did you look up what parseInt() gives back[^]?
OK - so you add the value from the box you typed in (a number) to the value in the box that has something that is almost certainly not a number: how can it give you any sort of result except that it is not a number (NaN) ? What do you get if you type your name in the box (instead of a number)? Or even with a number in the other?
One solution is to check the value and if parseInt() give you something that is not an INT then you set it to 0 . Are you doing that with in any way with your isNaN() test?
| Ravings en masse^ |
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| "The difference between genius and stupidity is that genius has its limits." - Albert Einstein | | "If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010 |
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hi
W∴ Balboos , thanks for the reply. Ive rethought the condition of the if statement and the following code seems to work. The only issue being if one of the text boxes is left empty then a NaN is given in the result . Just have to make sure the user puts a zero in for that hour just now to prevent that until i think of something else
regards
<pre> function sum() {
var txtFirstNo = document.getElementById('Text1').value;
var txtSecondNo = document.getElementById('Text6').value;
var txtThirdNo = document.getElementById('Text11').value;
var txtFourthNo = document.getElementById('Text16').value;
if(!(document.getElementById('Text1').value).length==0){
result = parseInt(txtFirstNo);
document.getElementById('Tar').value = result;
}
if(!(document.getElementById('Text6').value).length==0){
result = parseInt(txtFirstNo) + parseInt(txtSecondNo);
document.getElementById('Tar').value = result;
}
if(!(document.getElementById('Text11').value).length==0){
result = parseInt(txtFirstNo) + parseInt(txtSecondNo) + parseInt(txtThirdNo);
document.getElementById('Tar').value = result;
}
if(!(document.getElementById('Text16').value).length==0){
result = parseInt(txtFirstNo) + parseInt(txtSecondNo) + parseInt(txtThirdNo) + parseInt(txtFourthNo);
document.getElementById('Tar').value = result;
}
}
</script> 
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Two things I think you need to focus on learning: Console Log, and Typeof.
Javascript has a few primitive types of variables. It looks like you started going back and forth with int coming up as strings. I saw you put in parseInt which is what you need. What else may help is instead of putting things out to a browser element, you can access them with the Console.
Console = press F12 and look at the "Console". (Except IE because IE still sucks)
So you can try your first one with this:
console.log("Hello World")
This is rather important as next thing to try to see if a value is an Integer or not is this:
console.log(typeof myVar)
That should tell you Integer or String or Array. If you try to add a String to an Integer you get a hybrid and the Int is converted to a string.
var myVar = "Hello" + 12345;
console.log(myVar);
The output of that will be "Hello12345" Happens with Numbers also, which is when you end up with NaN or "Not a Number" which can be checked with "isNaN(var)".
So lets say you have this:
var varA = 10;
var varB = "20";
var sum = varA + varB;
Did you notice the quotes on varB? It means that although there are numeric characters in it, the variable is treated like a String, which causes varA to be typecast to a String. Your output there would be "1020" not the 30 like you expect.
Back to the console for just a moment. If you need to check the value of a variable or object or something in your code without jumping thru a thousand hoops to even see what that is, you can "LOG" that. In the console you can type your variable name. Simply type "varA" without the quotes and the console will output whatever the VALUE of varA is. You can also try putting in "typeof varA" (again, no quotes) and see if the VALUE is an integer or string, which is where I think you have the most trouble!
It doesnt fix your problem, but I hope this helps to undestand what the problem is and some of the tools you have available to you!
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15100276
Thanks alot for taking the time to reply in such a detailed way, its much appreciated. its a lot clearer now and the touchscreen project now sums the columns and ive added conditional formatting ...the coding would probably send shivers to your bones but tidying it up and making it more efficient is the next step. Again thanks for taking the time to reply.
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Dear Concern,
I am a new learner of javascript. Please expert will suggest to me, which is a good beginning project for understanding.
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Connecting to the question, I would be grateful for the answer 
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Just posting a link and not elaborating on your question is not a good way to get answers.
Describe the problem here, not on another site
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Hi, I am trying to read a value from Table Cell, but even if I am using parseFloat, Number or any function its always returning me null value, hence total is coming as null from the below code of JavaScript, any help please?
if ((m.PaymentPlan.ViolationsUniquePenaltyApplied != null) && (m.PaymentPlan.ViolationsUniquePenaltyApplied != 'undefined'))
for (let i = 0; i < m.PaymentPlan.ViolationsUniquePenaltyApplied.length; i++) {
let t = '#' + 'td0' + i;
let a = parseFloat($(t).html());
let b = Number($(t).html());
console.log('a');
console.log(a);
console.log(b);
totalRemaining = parseFloat(totalRemaining) - a;
console.log('totalRemaining');
console.log(totalRemaining);
}
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What is the actual text returned from $(t).html() ?
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when I try the code I get NaN, most likely because totalRemaining is not defined before it is used in the final expression.
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My total function as below:
saveTotalPenalty: function (paramdata, id, indx) {
var m = this.get('model');
let totalRemaining = m.PaymentPlan.TotalAmount;
this.penaltyPerUnit = $(this.boxId).val() / paramdata.Cnt;
this.penaltyPerUnit = this.penaltyPerUnit.toFixed(2);
if ((m.PaymentPlan.ViolationsUniquePenaltyApplied != null) && (m.PaymentPlan.ViolationsUniquePenaltyApplied != 'undefined'))
for (let i = 0; i < m.PaymentPlan.ViolationsUniquePenaltyApplied.length; i++) {
let t = '#' + 'td0' + i;
let a = parseFloat($(t).html().valueOf());
console.log('a');
console.log(a);
totalRemaining = parseFloat(totalRemaining) - a;
console.log('totalRemaining');
console.log(totalRemaining);
}
if ((m.PaymentPlan.ViolationsUniquePenaltyNotApplied != null) && (m.PaymentPlan.ViolationsUniquePenaltyNotApplied != 'undefined'))
for (let i = 0; i < m.PaymentPlan.ViolationsUniquePenaltyNotApplied.length; i++) {
let t = '#' + 'txt' + i;
totalRemaining = totalRemaining - $(t).val();
}
totalRemaining = totalRemaining.toFixed(2);
$('#thTotalRemaining').html(totalRemaining)
if ((paramdata.PenaltyAssessed == null) || (paramdata.PenaltyAssessed == 0) || (paramdata.PenaltyAssessed == 'undefined') || isNaN(paramdata.PenaltyAssessed))
return;
$('#td' + indx).html(this.penaltyPerUnit);
var scope = this;
var data = {
violationPenaltyAdjustment: paramdata,
CaseId: id,
PenaltyAssessed: paramdata.PenaltyAssessed
};
scope.api('Paymentxxxn/AddTotalxxxx').post(data).then(function (response) {
toastr.success("Payment added");
}, function (error) {
Ember.set(payment, "isLoading", false);
toastr.error("Error adding payment plan item");
});
}
modified 18-Feb-21 5:06am.
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I just tried with totalRemaining set to 5000, and the results are correct. There must be something else happening in your code.
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No actually when I am printing as below:
console.log('$(t).html()');
console.log($(t).html());
let a = parseFloat($(t).html());
console.log('a');
console.log(a);
console.log($(t).html()); is printing 1000 but after doing this, it is printing a value as NaN, any help please?
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Sorry, there is nothing more I can do. When I run those few lines of code I get the correct answer. But I cannot reproduce your problem since i do not have all the code.
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So, I am experimenting with recordRTC. I can create the recording and produce a webm file.
Now I need to upload it from the client to the server so I can convert it to mp4.
Any ideas how i can achieve this efficiently?
Thanks,
Ray
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I'm building an application with node.js, and I'm facing a problem connecting javascript or jquery with my node backend APIs. as an example: I can not do import to my controller APIs folder for the javascript or ajax, I tried to do ( type='modle') in config but it make it worse, show me errors for all my (require), so if there's an easy way to connect my scripts with my APIs I will be glad to you guys. even Axios (import axios from 'axios';) did not work with me. and I'm using pug template.
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Hi, I have this line of javascript code inserted in a function...
..
<b>select.options.add(new Option("Standard Floor Base (Base a pavimento Standard)", "SFB"));</b>
..
With this other line of code I access the properties of the "select"....
..
<b>select.classList.add("selectBlock");</b>
..
In the .css...
..
<b>.selectBlock{
font-size: 12px;
width: 290px;
height: 20px;
margin-left: 15px;
}</b>
..
Through a file . css recall the "class" "selectBlock" and change some properties inserted in the "select"...
<b>"Standard Floor Base (Base a pavimento Standard)"</b>
..
I wish I could change only the first part of the text inserted in the "select", exactly this text..
<b>"Standard Floor Base"</b>
..
Is it possible ?... thanks for the help...
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let elements;
let element_text;
let artistname = 'Hans Zimmer';
let spotify_window = window.open('https://open.spotify.com/search/Hans%20Zimmer');
setTimeout(function () {
}, 5000);
elements = spotify_window.document.querySelectorAll('._45331a50e3963ecc26575a06f1fd5292-scss._3957b7dd066dbbba6a311b40a427c59f-scss:not(.good-one)');
alert(elements[0]);
for (let element of elements) {
element_text = element.innerText;
if (element_text == artistname) {
element.click();
break;
}
element.classList.add('good-one');
}
the class name isn't wrong
https://ibb.co/sFTFt81
Also, if I execute the following code in that tab's console, it worked
let elements;
let element_text;
let artistname = 'Hans Zimmer';
elements = document.querySelectorAll('._45331a50e3963ecc26575a06f1fd5292-scss._3957b7dd066dbbba6a311b40a427c59f-scss:not(.good-one)');
alert(elements[0]);
for (let element of elements) {
element_text = element.innerText;
if (element_text == artistname) {
element.click();
break;
}
element.classList.add('good-one');
}
see:
https://ibb.co/PGn9cG4
then it clicked and jumped to the page
https://ibb.co/n6CPmvy
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Javascript in a page from one domain is not allowed to access or modify documents from another domain.
This is a security restriction. Imagine what would happen if code on evilbadguys.com was able to click the "Transfer all my money to the bad guys" button on the yourbank.com site!
There is no way around this, unless you want to try to convince all of your users to severely compromise the security of their browsers.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Hello everyone, given that I’ve just started reading HTML code and Javascript language, someone can help me solve this little problem, I’ll give you a generic example, imagine you have a table containing three "checkboxes" A, B and C, the same table contains three "radiobutton" position 1, position 2 and position 3,so for checkbox A we have the possibility to assign only one of the three radiobutton position 1 or 2 or 3 and so also for the other two checkboxes B and C, correspond only one of the three radiobutton, for example, we have selected the checkbox A and the radiobutton corresponding to position 2, I must ensure that, by selecting checkbox B or C, it is no longer possible to select the radiobutton at position 2, because it has already been chosen for checkbox A and so for any other combinations between these specific checkbox and radiobutton, I hope to have explained myself, some help or suggestion thank you.
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