DEV Community: Mehmet Bilgil

How To Create A GitHub Profile README

Mehmet Bilgil — Fri, 17 Jul 2020 20:00:15 +0000

Github presented another feature for developers last week.
You can add a README file to your profile, where you can provide information about your business and portfolio or anything. I will try to briefly explain to you how you can use this feature.
You are logging into your Github account and proceeding to the creation of a new repo. You create a repo with your username. At this stage, as you can see below, the private repo will be active:

Before completing the process, we activate “Initialize this repository with a README” and create the repo.
There is a template that you can edit in the first created README, if you have no idea, you can edit and use this ready-made.Otherwise, you should make the necessary arrangement with markdown.

Arrow Functions

Mehmet Bilgil — Sat, 23 May 2020 19:39:01 +0000

In this article, we will see how to use another important feature of JavaScript which is Arrow Functions.

Regular Function Syntax

Arrow Function Syntax

Difference Between Regular Function and Arrow Function

The value of this keyword inside Regular function depends on how that function was called (The object that made a call)

The value of this keyword inside Arrow function depends on where the function was defined (the scope that defined the function)

Regular Function gives access to its ‘calling‘ environment.

Arrow Function gives access to its ‘defining‘ environment.

Let’s understand this with an example;

We have defined two functions inside the const variable CallerObj. First one (func1) is Regular function and Second (func2) is Arrow function.

When you call both functions and see results in the console window of browser you see that func1’s this keyword value is associated with the calling object (CallerObj).

and, func2’s this keyword value is associated with the window object.

So, the conclusion is that in the Arrow function value of this doesn’t decide on who is calling it. It is decided at the time of definition of this.

Here are the results of the above code;

Single Line Function

An arrow function is useful where a function has a single line of code. For example, a function is returning some value.

Let’s look at examples,

1-Below is the Arrow function which returns multiplication values.
2-You can write this function in one line.

Example of map function which takes arrow function as a parameter.

There are several other uses of arrow functions but for learning React above points mentioned about Arrow functions are enough. If you want to go deeper then you can learn here more about them.

What is Deno ?

Mehmet Bilgil — Thu, 14 May 2020 18:59:34 +0000

If you are familiar with Node.js, the popular server-side JavaScript ecosystem, then Deno is just like Node. Except deeply improved in many ways.
Let’s start from a quick list of the features I like the most about Deno:

It is based on modern features of the JavaScript language
It has an extensive standard library
It has TypeScript at its core, which brings a huge advantage in many different ways, including a first-class TypeScript support (you don’t have to separately compile TypeScript, it’s automatically done by Deno)
It embraces ES modules
It has no package manager
It has a first-class await
It has a built-in testing facility
It aims to be browser-compatible as much as it can, for example by providing a built-in fetch and the global window object We’ll explore all of those features in this guide.

After you use Deno and learn to appreciate its features, Node.js will look like something old.

Especially because the Node.js API is callback-based, as it was written way before promises and async/await. There’s no change available for that in Node, because such a change would be monumental. So we’re stuck with callbacks or with promisifying API calls.

Node.js is awesome and will continue to be the de facto standard in the JavaScript world. But I think we’ll gradually see Deno get adopted more and more because of its first-class TypeScript support and modern standard library.

Deno can afford to have everything written with modern technologies, since there’s no backward compatibility to maintain. Of course there’s no guarantee that in a decade the same will happen to Deno and a new technology will emerge, but this is the reality at the moment.

Why Deno ? Why now ?

Deno was announced almost 2 years ago by the original creator of Node.js, Ryan Dahl, at JSConf EU. Watch the YouTube video of the talk, it’s very interesting and it’s a mandatory watch if you are involved in Node.js and JavaScript in general.

Every project manager must make decisions. Ryan regretted some early decisions in Node. Also, technology evolves, and today JavaScript is a totally different language than what it was back in 2009 when Node started. Think about the modern ES6/2016/2017 features, and so on.

So he started a new project to create some sort of second wave of JavaScript-powered server side apps.

The reason I am writing this guide now and not back then is because technologies need a lot of time to mature. And we have finally reached Deno 1.0 (1.0 should be released on May 13, 2020), the first release of Deno officially declared stable.

That’s might seem to be just a number, but 1.0 means there will not be major breaking changes until Deno 2.0. This is a big deal when you dive into a new technology - you don’t want to learn something and then have it change too fast.

Similarities and differences with Node.js

Since Deno is basically a Node.js replacement, it’s useful to compare the two directly.

Similarities:

Both are developed upon the V8 Chromium Engine
Both are great for developing server-side with JavaScript

Differences:

Node is written in C++ and JavaScript. Deno is written in Rust and TypeScript.
Node has an official package manager called npm. Deno does not, and instead lets you import any ES Module from URLs.
Node uses the CommonJS syntax for importing pacakges. Deno uses ES Modules, the official way.
Deno uses modern ECMAScript features in all its API and standard library, while Node.js uses a callbacks-based standard library and has no plans to upgrade it.
Deno offers a sandbox security layer through permissions. A program can only access the permissions set to the executable as flags by the user. A Node.js program can access anything the user can access.
Deno has a for a long time envisioned the possibility of compiling a program into an executable that you can run without external dependencies, like Go, but it’s still not a thing yet. That’d be a game changer.

No Package Manager

Having no package manager and having to rely on URLs to host and import packages has pros and cons. I really like the pros: it’s very flexible, and we can create packages without publishing them on a repository like npm.
I think that some sort of package manager will emerge, but nothing official is out yet.

The Deno website provides code hosting (and thus distribution through URLs) to 3rd party packages: https://deno.land/x/