JavaScript is the original and common name applied towards most flavors of a scripting language that originated on NetScape Navigator. 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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6
votes
2answers
181 views

Idiomatic way to write JavaScript class that maintains state and tells you when that state has changed

I am an experienced C++ developer but new to JavaScript. I want to write an ES6 JavaScript class that maintains state. How do I tell when state has changed? I can think of two ways to do this. One ...
-1
votes
1answer
82 views

Javascript Closures to Separate Class [closed]

PROBLEM: In Javascript I use closures to encapsulated methods inside a class. It helps building hierarchy inside and minimize amount of methods at root, but they become lengthy. RESEARCH: Applied to ...
-2
votes
1answer
239 views

Functional programming, and pushing item to array [closed]

I'm studying functional programming and I'm having some question concerning array population. Actually, I'm trying to rebuild the Array.prototype.map function, and here's what I've got: ...
3
votes
1answer
60 views

A JavaScript IIFE prevents leaks to the global space as a closure? Is that the correct concept?

I see in the code or sometimes people talk about it, for some JavaScript code: (function() { var something; function someFunction() { // some code here } // do something ...
4
votes
1answer
152 views

Filtering request and responses in RESTful MEAN stack

I have a very basic RESTful service written using the MEAN stack (MongoDb, Express.js, Angular.js, Node.js) and utilizing the Mongoose ODM. Product schema var productSchema = new mongoose.Schema({ ...
4
votes
1answer
84 views

Convention to where to declare module.exports on Javascript files

Is there any convention to where we should declare the module.exports no Javascript/Node.js module files? Should it be in the beginning of the file like: module.exports = Foo; function Foo() { ...
4
votes
1answer
80 views

In SPA what happens in terms of memory and performance when user hops across all the pages?

Imagine a humongous web aplication built using Single Page Application framework such as AngularJS. With its each route it downloads a couple of HTML template files. Each of these template files ...
1
vote
2answers
5k views

how do websites detect my screen resolution

http://whatsmyuseragent.com/ tells you your screen resolution, javascript enabled,user agent and local time etc? User agent is a part of HTTP header. How do they know about other information? I ...
3
votes
1answer
137 views

Client Side Filtering or Server Side Filtering

So I am building a web-app. The app will be hosted on heroku and I using a MEAN Stack for development. The main purpose of the app is to allow users to search through data and be able to find a ...
0
votes
1answer
193 views

Confusion over Node as a “script” vs Node as a “server”

As I was beginning to tool around a bit with node, I was told that I needed to undergo a little bit of a paradigm shift since I was coming from a PHP background. I would ask questions like, "I have my ...
2
votes
1answer
152 views

Javascript Closure Style Similar to Java Class Structure

PROBLEM: There is a coding imperative (S. McConnel, Code Complete) that one shouldn't code on language, but by means of it, e.g. doing right style things even if language doesn't have some ...
2
votes
1answer
138 views

Suggestions for structuring complex json structures?

I can't find many tips for how to design complex json structures beyond the obvious tips of not trying to nest too deeply, using defined data types, etc. For example, if I have a location that needs ...
2
votes
1answer
113 views

Should constant values be in SHOUT_CASE when there is language support for them?

Referring primarily to here, it suggests that values which are constant in JavaScript (using the keyword const) should be named in SHOUT_CASE. I'm of the opinion though that mutability is much more ...
0
votes
1answer
101 views

When to use “is a” or “has a”? [closed]

In my node.js application, I have a queue class which has push and pop methods and a data property. I have an Event class which handles an event and pushes it on to the queue. If I think object ...
0
votes
1answer
147 views

Handling multiple asynchronous events - Wait for pending offers to process on new offer?

I have a programming problem, that I don't know how to solve. And while I have provided a sample of my code, I am interested in a conceptual answer on how to resolve this problem. On a tradeOffers ...
3
votes
1answer
55 views

Should I be returning promises from any function that uses them?

Promises is a fairly new pattern for me, so I'm still building my intuition for them. I recently came across a case where some code in an adapter-like bit of code was once synchronous, and then ...
2
votes
3answers
406 views

Are colons ok in a REST API?

I see many REST API examples with URIs like http://<whatever>/widgets or http://<whatever>/widget/123, for a specific thing. For most things I would just stick with the front slash, but ...
-3
votes
1answer
190 views

different between ES6 and Javascript [closed]

What is ES6? Is it JavaScript? Or multiple language supporter? I searched for it but can't understand it, especially the page on Wikipedia. Is it better than Javascript? And what can I do in my web ...
3
votes
1answer
97 views

Javascript Promise chaining [closed]

I recently started working with JS Promises. What I always like to do, is create function, which returns a Promise with the final desired result, but I only do 1 operation/then. Consider something ...
2
votes
1answer
2k views

Approaches to reduce cyclomatic complexity

I was running our code through JSHint, and decided to switch checks against cyclomatic complexity, and then went on long refactoring sprint. One place though baffled me, here is a code snippet: var ...
0
votes
0answers
82 views

AngularJS and NodeJS required version

I am new to the world of Javascript and their frameworks, and I feel a bit lost with this. I am trying to follow the official toutorial of AngularJS. In one of the first sections, it reads Install ...
4
votes
3answers
931 views

Starting an HTML canvas game with no graphics skills

I want to do some hobby game development, but I have some unfortunate handicaps that have me stuck in indecision; I have no artistic talent, and I also have no experience with 3D graphics. But this ...
0
votes
1answer
171 views

Looking for a way to interpolate a base URL that won't conflict with Underscore template code

At my workplace, we have dev and production environments, and a separate server that serves static files for each environment. In my code, I make references to the URL of this static file server. ...
1
vote
2answers
341 views

Do I need Bower for front end dependencies when I am already using composer?

I use composer for PHP dependencies. I was under the impression that for front end dependencies I should use Bower. So, I installed Bower and loaded my FE dependencies (Bootstrap, jQuery) using that. ...
-5
votes
2answers
135 views

Technology like SignalR but client side [closed]

I would like to program a software that will heavily utilize client side development (JavaScript), and I want to communicate with the server. Is there a way similar to SignalR where I can keep ...
5
votes
1answer
184 views

What is the most efficient way to implement a RESTful client app?

I am working on a web application for ranking some products based on some factors. The user send a search query to 5 restful webservices which by their turn send a response in a JSON format and ...
2
votes
3answers
629 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 ...
4
votes
2answers
351 views

Methods of separating front and back-end with full stack javascript?

Suppose I have a front-end which is mostly a single-page application written using angular, grunt, and bower. And suppose I have a backend, which is mostly just a REST API sitting on top of an ORM, ...
-2
votes
1answer
72 views

Is it better to have a single, more general directive or multiple type based directives in Angular?

Is it considered good practice to have: Single, general directive that has multiple data-* parameters and serial data is binded from controller Single, general directive that has config and serial ...
6
votes
1answer
84 views

Strategies to maintain contract between mocks and APIs

Using a mock instead of hitting a 3rd party API like Postgres or Stripe can often be necessary when writing tests. A problem I've seen is when the API can unknowingly diverges from the data the mocks ...
10
votes
3answers
299 views

How do you use duck typing in javascript without always checking for properties and methods?

I know javascript uses duck typing and at first I thought this would make polymorphism easy compared to strongly typed languages like C#. But now my functions that take arguments are littered with ...
44
votes
6answers
4k views

Does immutability hurt performance in JavaScript?

There seems to be a recent trend in JavaScript towards treating data structures as immutable. For example, if you need to change a single property of an object, better to just create a whole new ...
2
votes
2answers
127 views

Will Web Components in HTML Add Too Much Complexity? [closed]

The way I've been accustomed to User Interfaces is to see everything as a div. Where a div is essentially a box and they can be stylized in CSS. <div class='container'> <div ...
2
votes
2answers
181 views

Is equating a variable to a function that takes the same variable bad programming?

Is it improper programming to set a variable equal to the result of a function that accepts the same variable? The languages in question here are c#, javascript and PHP (not sure if this works in C ...
0
votes
2answers
350 views

How to scramble a word, keeping first and last characters the same?

I have a task, which is to scramble a single word, whose size is greater than 3 letters. The scrambled word must not be equal to the original, and the first and last letters of the word must remain ...
-1
votes
1answer
134 views

Synchronous architecture with asynchronous repository

In order to keep clean architecture of my node.js microservice I have controllers, services and e.g. repositories. I want a synchronous data flow: controller -> service -> repository -> service -> ...
4
votes
4answers
18k 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 ...
3
votes
0answers
365 views

How to avoid module dependency chain nightmare caused by transitive dependencies?

Many (most?) AngularJS folks seem to advocate for breaking AngularJS apps up into many modules. Brian Ford in his blog already states that packaging by layer (controller, service, etc.) is a "silly" ...
2
votes
1answer
83 views

Is it possible to not have a zero-indexed array with javascript? [closed]

I've been coming across some interview questions that mention within the question "... given an integer x and a zero-indexed array..." Is it necessary to mention zero-indexed array? What languages ...
4
votes
3answers
170 views

Javascript Closure Scope

I was reading the "Closures" section on the w3schools JavaScript tutorial and I don't understand how the last example works. http://www.w3schools.com/js/js_function_closures.asp The goal is to ...
0
votes
0answers
96 views

Using the Facebook Login button, how would I securely convey to my web app's backend that the user is authenticated?

Background: I'm building a web app using the most recent Facebook Javascript SDK to help with user registration and login. The backend is built in PHP, but that likely is irrelevant. The situation: I ...
0
votes
1answer
307 views

Why does a lot of Angular source code avoid enclosing the contents of a file in a closure?

I am assuming because it is a standard practice in the Angular world that, any sort of module system has to be wrapped as an Angular module and angular should be the only global variable used which ...
3
votes
1answer
188 views

Best-matching comparative values using all items in array

I have two arrays of objects (items) in the exact same format. Each item represents a wager, and each array represents one of two outcomes for that wager (ex: Team A vs Team B). Both arrays look ...
-1
votes
1answer
120 views

Inheritance hierarchy design approach - Javascript [closed]

For the below code, that creates inheritance hierarchy, function Animal(){ this.name = "Animal"; // toString is a function in the main Object that every // object inherits from ...
1
vote
3answers
302 views

Javascript Password Security [closed]

I am having difficulty with the answer provided here, but I couldn't understand how to implement it. My code is pretty much identical: <script language="javascript"> function check(form) { ...
3
votes
0answers
97 views

Tips for optimizing javascript code. a year's worth of Dates

I am playing around with the date object, i made a function that generates a bunch of dates, and applies some function on each date. For a month's worth, it is fine about 2.5ms on my pc, ff and ...
24
votes
2answers
9k views

What is ASM.js and what does it mean for everyone?

I'm starting to hear rumblings about this project called ASM.js. Currently their web site is terrible and confusing. Here's what I know from my research on the web. It is a subset of JavaScript that ...
4
votes
2answers
112 views

Check in which region is a geoposition Marker located in

I use Mapbox to display some moving markers over a map with several polygons drew over it (feature layers). I have serveral markers (~1000) and multiple feature layers (polygons ~200) that represent ...
3
votes
1answer
124 views

Are there practical benefits from encapsulating JS inside class.create?

I am working on this web application that already has a mechanism that allows a developer to define server side JavaScript functions that can then be called by other server side JS code. There are ...
3
votes
1answer
241 views

Best practice for angular service return value

I have a number of angular services (e.g. a user service) which make various HTTP calls and I'm wondering what the best practice would be for handling errors. For example, I could do: function ...