Real-life: scan() a wallet balance

Show the running balance after each operation: +10, -3, +5.

1. Solve the task in the editor — no long theory.
2. Run the check and compare your output with the expected result.
3. Stuck? Open the solution and carry the approach into your own code.

const { from, scan } = Rx;

const operations = [10, -3, 5];

const result$ = from(operations).pipe(
  scan((balance, change) => balance + change, 0)
);

result$.subscribe(value => console.log(value));