test-routing-snapshot-example.ts

@Component({
    selector: 'app-dummy-component',
    templateUrl: './dummy-component.component.html',
})
export class DummyComponent implements OnInit {

    constructor(public route: ActivatedRoute) {
    }

    ngOnInit(): void {
        if (this.route.snapshot.queryParams[QueryParamNames.id]) {
            // load the item and show the edit form
        } else {
            // load the creation form
        }
    }

}