Playing with async function

 Async/ await is cool feature in JavaScript. Much has been written about it. In this post I would like to show how to resolve more independent async functions calls.

Let's have a simple promise call. It takes 1 second.

Now we will call the function multiple times using await. It takes aproximately 10 seconds.

When our asynchronous function is independent, it is useful to use Promise.all() instead of await. It fulfilled all promises in time approximately 1 second.

Javascript closures and recursion

What is a closure?

A closure is a feature in JavaScript where an inner function has access to the outer (enclosing) function’s variables.

I think, that closures are very handy for recursive call.

What is a recursion?

Simply said, the process in which a function calls itself.

When you create a recursive function, keep in mind that there must be an escape from the recursive function, otherwise you will get into an infinite loop.

Below I created a function, which call yourself. Recursion can be very complex, but the principle is the same.

Try it yourself:

Simple accordion on your website

Hey guys! Do you know about details and summary HTML5 tags?

This creates a simple accordion on your website. It si simple and elegant, isn't it?

Example:

JavaScript

JavaScript (/ˈdʒɑːvəˌskrɪpt/),[10] often abbreviated as JS, is a programming language that conforms to the ECMAScript specification.[11] JavaScript is high-level, often just-in-time compiled and multi-paradigm. It has dynamic typing, prototype-based object-orientation and first-class functions.

Node

Node.js is an open-source, cross-platform, back-end JavaScript runtime environment that runs on the V8 engine and executes JavaScript code outside a web browser. Node.js lets developers use JavaScript to write command line tools and for server-side scripting—running scripts server-side to produce dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm,[6] unifying web-application development around a single programming language, rather than different languages for server-side and client-side scripts.

Lookup map in JavaScript

Hey guys! Do you know if statement? Of course yes! But do you know lookup map? It's an elegant way to solve a multiple conditions.

Instead of using if..else, switch, we can define in advance a lookup table of values based on certain key.

Let's look at an example: