how to use the from function from the rxjs library in javascript

The from function in the rxjs library is used to create an Observable from an Array, an array-like object, a Promise, an iterable object, or an Observable-like object.

To use the from function in JavaScript, you first need to install the rxjs library either by downloading it to your local project or using a CDN link. Then, you would use the from function in conjunction with the Observable constructor to create an Observable from the desired source.

Here is an example of using the from function to create an Observable from an Array:

index.tsx
const { from } = require('rxjs');

const array = [1, 2, 3, 4, 5];

const observableFromArray = from(array);

observableFromArray.subscribe(
  value => console.log(value),
  error => console.log(error),
  () => console.log('Complete')
);

// Output: 1 2 3 4 5 Complete
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14 lines

In the code above, we first import the from function from the rxjs library. Then, we create an Array and assign it to a variable called array. Next, we use the from function to create an Observable from the array variable, and we assign the new Observable to a variable called observableFromArray. Finally, we subscribe to the observableFromArray and log each value that is emitted, along with any errors and the completion of the Observable.

This is just a basic example, but the from function can be used in more complex scenarios to create Observables from other sources as well.