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TypeScript is a superset of JavaScript, so some datatypes are inherited from it. But TS introduces many more helpful data types. Let’s break them down in the following list.


Logo dell’Organizzazione Mondiale della Sanità
Logo dell’Organizzazione Mondiale della Sanità
Logo dell’Organizzazione Mondiale della Sanità

Questo articolo vuole essere una divulgazione quanto più possibilmente fedele per coloro che non conoscono l’inglese e che vogliono essere tenuti al corrente delle novità e/o raccomandazioni da parte di un ente globalmente riconosciuto che quotidianamente pubblica tutti gli aggiornamenti scientifici e suggerimenti di ogni sorta, per affrontare tutti insieme questa emergenza mondiale che ha colpito molto gravemente anche l’Italia.

Le seguenti domande e risposte sono la traduzione letterale (che cercherò di tenere il più aggiornata possibile qualora dovessero esserci novità e/o modifiche) della pagina FAQ del sito web dell’Organizzazione Mondiale della Sanità (OMS — World Health Organization, WHO…


As a developer, you may remember the functionality that Firefox was using some years ago, where you were able to see in 3D, the page you were working on, and understand immediately the z-index of the elements and eventually have an idea about which one was covering the other.

It was a good utility that a certain point was removed, maybe because it was not used very much (it was useful just for developers not for the final user) and it was giving the browser some sort of slow interaction.

The Trick

With the following code, you cannot see the page…


Did you bought a brand new Bluetooth headphones but you are not able to connect them to your computer? Or maybe they are working with your computer but your smartphone is not able to find them even if the Bluetooth is activated in both the systems?

The answer is really simple, once the headphone have been paired with the first device, they do not enter in pairing mode anymore when you switch them on again. This is because when you pair a 2nd or subsequent device, the headset has pairing information for other devices.

The re-activation of the “pairing…


Let’s share environment variables between Front End and Back end and pass them to and Angular application.

I really like the environment variables setup with the Angular CLI. One problem though is that sometime I need to pass to the app some keys or maybe some links that I do not want to commit on the repository (inside the environments.ts files, even if the repo is private). This is due to many reasons:


Let’s install different Angular releases in our local machine (works with AngularJS, Angular 2, Angular 4, Angular 5, Angular 6, Angular 7)

In a day to day job as a developer, sometimes we are asked to jump or to work with projects that are using different Angular releases.

This is due to many factors:


detect touch devices with only CSS
detect touch devices with only CSS

New standards developments in CSS are providing a better future for developers that needs to detect touch devices just with their CSS.

CSS Media Queries Level 4 indeed is going to provide 2 new features: hover and pointer.

Interaction Media Features: Hover

The hover media feature is used to query the user’s ability to hover over elements on the page with the primary pointing device. If a device has multiple pointing devices, the hover media feature must reflect the characteristics of the “primary” pointing device, as determined by the user agent.

With the words “primary” pointing device, the W3C draft intended the primary…


Have you ever faced the problem that the HTML tag select has with its default style and arrow appearance on different browsers? Especially on the older Internet Explorer browsers?

Well, if the answer is “YES”, or maybe you want a drop-down arrow that appear the same in each browsers (including the old ones), here there is an easy trick.

It’s all CSS, no JavaScript needed!

Do you want to see it in action first? Take a look at these examples with all your browsers!

Now, let me explain how this solution works.

Drop-down Arrow for Chrome, Firefox, Opera, Internet Explorer 10+

For these browser, it is easy to set…

Riccardo Andreatta

Front End Developer

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