example

//codice che non funziona
this.carsService.getCars().pipe(
    filter(car => car.userId == this.userId)) // Property 'userId' does not exist on type 'Car[]
    .subscribe( cars => {
        console.table(cars);
    })

//soluzione
this.carService.getCars().pipe(
    map(cars => cars.filter(car => car.userId == this.userId))
    .subscribe( cars => {
        console.table(cars);
    })

//carsService.ts
 getCars(){
    let options = {headers:this.headers}
    return this.http.get<Car[]>(this.host + 'getCars', options);
  }

// Car model
export class Car {
    username:string;
    id:number;
    model:string;
    brand:string;
    userId:number;
}