import { Observable, of } from 'rxjs'; // #docregion import { map } from 'rxjs/operators'; const nums = of(1, 2, 3); const squareValues = map((val: number) => val * val); const squaredNums = squareValues(nums); squaredNums.subscribe(x => console.log(x)); // Logs // 1 // 4 // 9 // #enddocregion