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RxJS basics − observables

The main concept of the RxJS library is Observable, which is an abstraction for an array of items over time (that is, a stream of values).

Observables can do the following:

• Be subscribed to (that is, observed)
• Emit values when they become available
• Automatically push the values they emit to their subscribers (depending on the type of observable!)

Creating observables is easy, and RxJS provides operators which can create Observable instances from different sources.

Here are a few examples.

The of (https://www.learnrxjs.io/operators/creation/of.html) operator lets you create observables from a set of values:

import { of } from 'rxjs'; 
const myObservable = of(1,3,3,7); 
//... 

The from (https://www.learnrxjs.io/operators/creation/from.html ...