In rxjs version 6+ they removed the from operator from the Observable class. So now you need to import from rxjs and use without appending the Observable class.

component.ts                                    

import { Component } from '@angular/core';
import { from } from 'rxjs';
import { filter, map, } from 'rxjs/operators';
@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  name = 'Angular';
  description!: string;

  constructor() {


    from([1, 2, 3, 4])
      .pipe(
        filter((e: number) => e % 2 == 0),
        map(e => e * e)).subscribe(
          e => console.log(e),
          error => console.error(error),
          () => console.log("Done！")
        )
  }
}

Here is solution on stackblitz                                    

Hope this will help!

• Thanks a lot, I have tried, now it's working ! :) – puddlejumper26 Mar 29 at 2:19                                                
• I'm glad I could help. Please accept the answer so others will get benefit out it – TheParam Mar 29 at 3:34                                                

Import from directly

import { from } from 'rxjs';

from([1,2,3,4])

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

• thanks a lot, it works! :) – puddlejumper26 Mar 29 at 2:19