Javascript Tutorials

JavaScript object how to use Foreach loop

JavaScript's Array#forEach() function lets you iterate over an array, but not over an object. You can iterate over a JavaScript object using forEach() using Object.keys(), Object.values(), or Object.entries().

MapboxGL is not defined error solution

Fix mapboxgl is not defined. it's an easy fix you just have to include mepboxgl script into your Head section.

Mapbox production error in console Uncaught Reference Error

Fix Mapbox production error in console. "Uncaught ReferenceError: y is not defined". with Mapbox 2.0 version React app in the production environment gets this error and it's really easy to fix it.

Essential javascript array functions

Much more efficient and flexible Essential javascript array functions to use in daily routine. Great Power at no performance cost.

Javascript Questions

How to get response from firebase after set?

Function creategame(gameid, pin, currentdatetime, playername) { firebase.database().ref('games/' + gameid).set({ pin: pin,

HEROKU Error: ENOENT: no such file or directory, stat '/app/distpublic/index.html'

I know there are alot of questions like this on the site but i ihave tried everything i could on this site, the best i could get to work on heroku

Heroku Error: ENOENT: no such file or directory, open '.env'

I'm trying to push my application to heroku, but i'm running into some issues: error: enoent: no such file or directory,

Heroku : Error: ENOENT: no such file or directory, open '/app/build/index.html'?

My directory :

"Failed to execute 'querySelector' on 'Document': 'class MyComponent extends HTMLElement" during Karma test

I am getting the error mentioned in this question head. i don't understand why i can't check if certain div id is available. it is quite simple

Cannot assign to 'MyComponent' because it is not a variable (react-dnd multi drag&drop support in ReactJS

I would like to have drag and drop at the same time using react-dnd // ... imports ... class mycomponent extends

Trouble adding onclick handler to hyperlink tag inside listitem

Trying to add an onclick handler to my tabs, and can't seem to get the dom selection right. can you guys help? <div

Do I need to keep bootstrap.js in Laravel?

When i created my laravel project, there's a file called bootstrap.js in resources/js. i'm not using vue or any js

Module not found: can't resolve 'moduleName' in react js

While learning react js from official documentation

What is the meaning of the square brackets in “.module("modulename", […])” of AngularJS

I just saw an example of routing in angularjs. i would

Ember 1.12 Cannot read property 'moduleName' of undefined

I updated my ember version from 1.11 to 1.12 and now i'm getting this error message on console when trying to run the app:

Getting only one <modulename>.nocache.js file in Multiple Entry Point Module

My project structure has two entry point methods on client side in extrygate.java exitgate.java i have also

prototype methods do not visible in constructor if module load with require('moduleName')

I have a simple module, it's code var router = function(pattern) { this.setroutepattern(pattern); };

React Navigation V4: Swipe on drawer does not work in Android

I have been searching for a solution for a long time but in react navigation v4 there is no answer i have created a simple drawer

React - componentDidUpdate() is unable to find DOM objects rendered by the render() method

Edit: i've edited the code to add and use refs instead of document.getelementbyid. it didn't fix the problem.

To show/hide a Form.control based on check/uncheck from Form.check in react bootstrap

I am pretty new to react and bootstrap. i want to know - how can i control the visibility of a form.control when form.check is checked or

Method “simulate” is only meant to be run on a single node. 0 found instead

I am learning enzyme with react but i am facing this problem can any one help me out . i am trying to test register page on change username and

Slider API of Material is not render the slider properly in case of fraction number as step, marks | material ui | Slider | React

I have a react application on which i am going to add the material ui slider. but i can't able to create the slider properly. i don't know which

Access constructor variables inside the render method - Reactjs

I have a simple registration form as shown in the below code and is aiming to do display my validation message on submit. the code is mostly in

How to convert string hours to 'hh:mm:ss' format?

I'm getting my google api response for duration like 1 hour 13 minutes i need to covert this to 'hh:mm:ss' format.how to convert this

Javascript deep copy without breaking dates

I would like to make a deep copy (break references) without turning date objects into strings, how would i do that?

async/await: wait for loop end before return function result

I have next function: async getpopular() { return await

Weird behavior in displaying textContent when there's overflow

I am making a calculator app and there i am noticing a weird glitch. when i enter "1-1111...." and the moment it overflows the

How to remove # from URL and 404 reload issue in angular build and nodejs application?

I have angular9 and nodejs application. i am doing ng build --prod for production build and putting that build file inside nodejs

Call function after event is called from bootrap file

Theres a modal that open on click of some div .i want to extent the close or mouseout event of this modal(which is defined in bootrap.min.js).by

Required props undefined in chrome 83

So after installing chrome 83 one of my pages in my app crashes. it says some of my props that's required is undefined. this only happens in

How to Slice character and display in HTML file in Angular 8

I have below string which i am displaying in html file from api response. for ex - test,abc,red,blue,green

Asp.Net core MVC Javascript Ajax parameters null HttpPost

I am writing a javascript function for a button <button type="button" class="btn btn-sm btn-outline-secondary"

text file to arraylist javascript

I have a txt file on mydomain.net/file.txt.how can i read this into an array filecontent where each new line is a

How to edit style of negative x grid lines on Chart.js?

I want to draw dashed lines on the x-axis for the negative value on my chart, how i can do that?

How to find index of an array that contains specific array in it?

I'm developing a ecommerce cart, in the following cart each item could have some "variants", the item model looks like the following where

Angular not setting correct form validation classes in tests

There seems to be an issue with angular applying validation classes in unit test environment. by validation classes i mean ng-valid

I get error when sending data using express from node server to client side JavaScript

I am making a post call from ajax to node server. server makes the call and gives the response. but also below error displays in the cmd

How to delay a button display to 2s in Vuejs

I have a button component which i am using in several places. but i want to show that button after 2s on a specific page. how can i achieve this

How can I loop for multiple classes in jQuery?

I want to make a loop instead of adding javascript for each element to show the div on first click and hide the div on second click. only

How to remove cache after a new build react project

When we have a new build in our react project, users who work with our pwa because they have old cache they cant have our last changes and they

Should I use onclick or click method inside jQuerys document ready?

I don't know if i should use onclick in html/php or a single click function bound to a specific id. onclick example:

Why are all my child components re-rendering despite having keys?

I was playing around with react-dev-tools chrome extension and found out that all my components are re-rendering.

How to alert URL exclude filename.php in javascript?

I have tried this alert but not getting result what exactly i want suppose my url =

Using a variable to switch between input arrays

I am trying to use the value from a drop down list to reference an array which i am using to load some data via an api in the backend. so the

I want to declare the values of the objects within the class and only call the keys when Im declaring a new class. What could I do?

This is what ive done so far. class pricecalc { constructor(obj) { this.parts = object.keys(obj); this.cost = "$"

ES module path alias in browser

I would like to use es modules in browser environment in a convenient way like: import react from 'react'; import

How do I multiply values from different inputs to get a total using Javascript?

I am trying to do a shopping cart where i want the total to automatically change after the quantity is inputted (the total is the price times the

How to change the color of navigation bar using a button click in javascript?

I made a page where the user could change the page's body/header/footer's background color by inputting the color into a textbox. my functions

How to access KeyValuePair collection as JSON array

I'm making ajax calls to a page in asp.net core 3.1. the response is a jsonresult whose value property is an

What is the better way for passing props to component in React?

Which is better in passing props? passing the whole object as props? or passing them separately? e.g title="sample"

Build table dynamically with PDFmake

I found an example of how to fill the table with pdfmake dynamically, which has 2 columns. now i tried add another column 'height' to the table

How can I open multiple pop-up windows using js?

I'm currently working on an art project and i would like to know how to open multiple pop-up windows in order to make it look like one of those

my number input should accept only numbers[0-9] and [-] character

Should accept and [0-9] and [-] character and it should be max and min 12 characters and 123-456-7890 format

How can i fix Mixed Content issue in mqtt?

I need to connect to broker over websocket. <script

Javascript String concatenation faster than this example?

I have to concatenate a bunch of strings in javascript and am searching for the fastest way to do so. let's assume that the javascript has to

Simplest SOAP example

What is the simplest soap example using javascript? to be as useful as possible, the answer should: be functional (in other

Looking for a simple JavaScript example that updates DOM

I am looking for a simple javascript example that updates dom. any suggestions?

Where do I set a HTML file/page in the root of my React Project to land on example.com/login.html?

I am trying to authenticate a user using a third-party auth server. their redirect_uri states after the user logs in, they will be redirect to

Angularjs route doesn't load login.html into main.html?

While i am trying to do a single page application using angular.i am unable to load login.html view into ng-view of main.html.kindly some one help

GWT: Static HTML pages should redirect to login.html if not logged in an application

In my application i have some help pages. those pages can be accessed from app when you log in. but if some one bookmarks them they are still able

How can I validate an email address in JavaScript?

I'd like to check if the user input is an email address in javascript, before sending it to a server or attempting to send an email to it, to

I am passing msg from Child1 to Child2 via Parent.But this.prop showing values inside render() but not anywhere else in class

Import react, { component,fragment } from 'react'; import child1 from './child1' import child2 from './child2' class parent extends

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