Questions tagged [javascript]

JavaScript (not to be confused with Java) is a high-level, dynamic, multi-paradigm, weakly-typed language used for both client-side and server-side scripting. Use this tag for questions regarding common implementations of ECMAScript, JavaScript, JScript, etc. JS does not typically refer to its ECMA-cousin, ActionScript.

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2
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1answer
101 views

How should I define hardcoded strings with some variable parts? Reuse more characters? Or keep the whole sentence?

for example, sometimes I need to define a hardcoded string with some variable parts, I often have trouble to choose the style: style 1 : reuse every characters when possible showMessage(num){ let ...
6
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2answers
2k views

Memory usage of JavaScript string type with identical values

JavaScript string type is immutable, but does it mean identical strings will share memory? Say two strings are created in complete different places, will a modern JavaScript engine be smart enough to ...
-1
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2answers
267 views

How to process a login form data?

I have created a login form for my website, but the issue is how to process the data provided in the form by the uses. You see, I can't just write a basic function like this one - myfunction(){ if(...
2
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2answers
112 views

An options parameter vs chained functions for object initialization?

What concrete objective advantages do chained functions have vs an options parameter for object initialization? What do I mean? Well as one example there's a library called dat.GUI that uses the ...
1
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1answer
100 views

OrderedMap or List for Redux structure?

I'm implementing a Redux store for a React app using redux-saga for API calls. I've used Immutable.js before for other Redux-using React apps but the nature of previous projects always evidently ...
3
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2answers
564 views

What is the right time to go for Code Refactoring, not optimization?

I've been working on a Python(Django)/JavaScript(AngularJS) based application for some time now.(I learnt all of these on the way, had previously been a Java only programmer)and have hit moments where ...
0
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0answers
193 views

Event loop task and micro tasks order execution

I m actually studying different part of the event loop in javascript and I'm stuck understanding the execution order of the tasks from the task queue and the different microtasks. For now, running ...
1
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2answers
1k views

Supporting multiple javascript frameworks in eventual single application

We are building several applications that will eventually be one front-end application. It is split up into several projects at the moment where each project is managed by its own scrum team. The ...
0
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1answer
105 views

How to build a data-driven menu in JavaScript?

I'm going to attempt to build a data-driven menu for my web-app. The goal is to be able to serve different menu options to different users from an API. The hope is that the server could return a ...
3
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1answer
193 views

What's the best way to handle a large multi-file class in Javascript?

I have a very large class of 59 methods and about 3000 lines of code. I know that's far larger than most people would want, but the class represents a virtual machine, and most of the methods are run ...
0
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0answers
29 views

Promise, Ecmascript and Whatwg event loop

I've recently learned that setTimeout is not part of Ecma 262 standard but takes part of WhatWG one. I have one misunderstanding concerning these two standards and I can't get how they converge. For ...
0
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1answer
44 views

Can websites written in JavaScript make requests to SOAP API's?

I have an API written in SOAP 1.2 that I am trying to give to a developer whose website is written in Javascript and said they can not request the file because they do not know PHP. From my ...
1
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1answer
142 views

Strategy to deal with huge data

I have a Spring based java webservice which is returning JSON response. The problem is that the JSON response takes long time because the SQL involved is querying huge chunk of data and it takes 4-5 ...
10
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5answers
76k views

Falsy values vs null, undefined, or empty string

I've worked with jQuery over the years. However, recently, I've found myself getting deeper into the JavaScript language. Recently, I've heard about "truthy" and falsey values. However, I don't fully ...
-1
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1answer
53 views

Difference in use-cases for just using '.catch' v.s using 'Throw Error…' with '.catch'

If .catch catches any errors upon request attempt, why would I need to use Throw Error... with .catch? For instance, what is the throw Error used for, that the .catch doesn't handle automatically? ...
2
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2answers
347 views

Should I use Array or Set if both can be used to finish my task?

for example, Suppose I have a 2d array: let filterArr=[ [1,1,0,1,1], [0,1,1,1,0], [1,1,0,1,0] ]; I want to find and store the index of column that all are 1, i.e.:position 1 and 3, and the ...
2
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1answer
130 views

Resolving request congestion at browser by using socket as “fast lane”, any consequence?

I have received multiple reports from users of a Web-based GIS application we have rolled out one to two year ago, complaining the application becomes unstable/unresponsive. After a brief ...
0
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1answer
64 views

ReactJS - proper way to handle a responsive design approach?

I've always used CSS and media queries when it comes to responsive design. I've been developing in ReactJS for a while, but I feel my approach to responsive design is sloppy. I find myself using a mix ...
1
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1answer
385 views

How to dynamically add new posts once they are created

I am trying to design an application where users can make posts with Django on the backend. Right now I have to refresh the page with JavaScript every 20 or 30 seconds to check for new posts that ...
2
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2answers
7k views

Visual Studio build everytime JS and CSS changes?

I am relatively new to Visual Studio Development and I was wondering - it seems that everytime I make changes to my JS or CSS in my project - I have to "build" the project again. Is there any way to ...
-3
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4answers
285 views

Might there be two types of a “callback” in programming? [closed]

I know two definitions for a "Callback": A function that is being called-after ("called-back when") a certain event is triggered. A function that is passed to another function as a parameter. An ...
-3
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2answers
225 views

Is this an anti pattern in Javascript?

A common pattern I've been using for JS/NodeJS applications is the following: import { utility1, utility2 } function exampleScript() { utility1() utility2() // Does something } Basically my main ...
0
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0answers
64 views

Naming convention for string constants and string functions

I'm creating a react application, and I want to keep all my string constants in a single file like: export const STR_LOGIN = "Log in"; //h1 on a login page export const STR_USERNAME = "Username"; // ...
4
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0answers
302 views

Should an SPA use OIDC's Implicit flow or Auth Code flow?

We are developing a new Angular SPA which leverages Keycloak for its SSO abilities using OpenID Connect (OIDC). The app is currently designed to use the Implicit flow to retrieve short-lived access ...
0
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1answer
139 views

Is JavaScript unique in the way it treats missing property access?

Javascript has the behavior where an error is not thrown on missing property access on objects, which is the cause of many pernicious bugs: console.log("iPhone".missingProperty) // undefined I'm ...
2
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2answers
142 views

Is it conventional to use both await and .then()?

I've written a bit of code that looks like this: async function fetchData() { const json = await fetch(ENDPOINT + key.key).then(data => data.json()); //Do something with the data } It's ...
0
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1answer
264 views

What is it that is so hard about ES6 modules for Node? [closed]

It seems like ES6 imports for Node have been a bugbear for a while. There is the --experimental-modules flag, or options like using Babel - but AFAIK ES6 modules still aren't supported in vanilla Node....
1
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3answers
1k views

Object.defineProperty vs get/set

What is the difference and when would you prefer to use Object.defineProperty vs get/set methods in javascript for getters / setters? Ex: class Foo { constructor () { Object....
3
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2answers
301 views

How can I avoid using global variables in simple Javascript SPA?

To learn Javascript I am building a simple Single-Page Application. It is a basic slideshow app that needs only to process some basic settings and execute some behaviors. The basic structure of my ...
45
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8answers
56k views

Why almost no webpages hash passwords in the client before submitting (and hashing them again on the server), as to “protect” against password reuse?

There are many sites on the Internet that require login information, and the only way to protect against password reusing is the "promise" that the passwords are hashed on the server, which is not ...
1
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1answer
251 views

Why bother with server-side form submissions in a SPA?

I am all in favour of progressive enhancement and using server-side rendering when fetching a URL. The age-old discussion gives several advantages, such as improved load time, SEO crawling and ...
1
vote
1answer
3k views

Javascript idioms this that vs this self [closed]

I've been writing JavaScript for a bit and have now seen code using the idiom var that = this; and var self = this; Used to gain access to this through closure scope. At this point var self = ...
5
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3answers
2k views

How does JS Promises works being single threaded

Javascript is single threaded. What I understand from this is if JS i executing on line of code lets say a function. It cannot go to the next line unless that function has been removed from the stack. ...
61
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15answers
17k views

Is there any reason not to go directly from client-side Javascript to a database?

Possible Duplicate: Writing Web “server less” applications So, let's say I'm going to build a Stack Exchange clone and I decide to use something like CouchDB as my backend store. If I use their ...
28
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10answers
3k views

How does a programmer used to static languages cope with lack of Javascript tooling

I have programmed pretty much exclusively in compiled languages, particularly Java, for most of my career. One of my favourite things about Java is how productive you can be, and how little code you ...
15
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6answers
27k views

Is it better to put the JS code on the html file or in an external file?

If I'm designing a one page website, is it better to create external file for my JS code, or just put it in the html code? Is putting it on the page faster to load? Can I change the permissions to ...
1
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2answers
2k views

How to make scalable modules in a div element

I'm interested in creating web modules that are encapsulated by a div element in a manner that, by simply resizing the div, everything in that div scales to the dimensions of that div proportionately (...
2
votes
0answers
66 views

Is there a recommended design/architecture when developing a JavaScript module?

Practicing some of the ES7 features, I started developing a class to perform some actions on the DOM and use the new features. I used Babel to make it work on the browser, and the code looks something ...
5
votes
1answer
749 views

Different type of MEAN Stack Architectures

I am reading a book (Getting MEAN by Simon Holmes) about MEAN Stack which talks about different architectures that can be used while developing an app in MEAN Stack and I got a little confused with ...
15
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4answers
7k views

Where should I do localization (server-side or client-side)?

I am currently developing a new web application based on a rich JavaScript client which communicates with multiple REST web services on my server. That application is intended to be used in at least ...
1
vote
1answer
1k views

Preserving Pre-formatted Multi-Line Strings in Node.js Scripts

There is a lot I don't like about PHP, but one thing I love is multi-line strings: $query = <<<EOT select field1 ,field2 ,field3 from tableName where field1 = 123 EOT; What'...
0
votes
1answer
293 views

What is the use of the prefix “for(;;);” in an Ajax response

After using the chrome debugger to inspect the ajax requests of Facebook (for curiosity), I noticed that the response is in JSON, however it is always prefixed with for(;;); In example, if the JSON ...
1
vote
1answer
85 views

Should this part of my web-app implemented on server-side or client-side?

I want to write an application which monitors a few URLs (like a couple hundred) of all branches of school. By monitoring, we mean that it sends requests to those URLs at regular intervals (Interval ...
21
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3answers
34k views

How to run C++ code in browser using asm.js?

An asm.js application is very fast (near native C++ speed): http://kripken.github.io/mloc_emscripten_talk/micro4b.png But how is it possible to write one in C++, convert it to LLVM code, then do ...
0
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0answers
113 views

Is giving sub reducers access to the full state a bad idea?

I've got a Redux app with a fairly flat state tree. All sub reducers handle one separate part of the state, and they are tied together with combineReducers. My problem is that in a few cases I need ...
20
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4answers
8k views

Why is JSX good, when JSP scriptlets are bad?

React.js provides JSX as an XHTML-like syntax for constructing a tree of components and elements. JSX compiles to Javascript, and instead of providing loops or conditionals in JSX proper, you use ...
0
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0answers
46 views

JS ecosystem - In which oder I should learn them?

I'm migrating from Java to JS and I would like to know what is the best way to do it in the field of JS ecosystem. After reading all the You Don't Know JS series by Kyle Simpson, I would like to ...
-3
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1answer
4k views

How can I do to use Angular 5/6 for frontend and Codeigniter 3 for backend in the same web app?

I have this project I want to do, using Angular 5/6 for frontend and Codeigniter 3 for backend. The problem is that I don't know how to combine the two, and all the tutorials I looked were using ...
1
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1answer
84 views

Simulating Comparison Without Using Comparison Primitives

In the same way that you can simulate the if statement and functions, I am wondering if there is a way to simulate the comparison operators ==, !=, >, >=, <, <=. For example, in ...
7
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3answers
11k views

Is it bad design to internally call API endpoints from within the API instance?

For context, I am running a REST API built with Node.js. Because of callbacks and some complex DB calls, I have a chain of functions that are async but also unique, so it's tough to reduce redundancy. ...