angular how to check previous route
//Update angular 6+
//The events.filter gives error because filter is not part of events, so change the code to
import { filter, pairwise } from 'rxjs/operators';
this.router.events
.pipe(filter((evt: any) => evt instanceof RoutesRecognized), pairwise())
.subscribe((events: RoutesRecognized[]) => {
console.log('previous url', events[0].urlAfterRedirects);
console.log('current url', events[1].urlAfterRedirects);
});