Optional chaining property with 0 value

Asked Apr 20 '23 at 10:20

Active Apr 20 '23 at 11:00

Viewed 68 times

I have such code:

if (action?.notificationKey && state.notifications[action.notificationKey]) {
    delete state.notifications[action.notificationKey];
}

which does not satisfy me, because action.notificationKey can have 0 value and optional chaining condition is not fulfilled.

refactoring to:

    if ("notificationKey" in action && state.notifications[action.notificationKey]) {
      delete state.notifications[action.notificationKey];
    }

does not satisfy TS, and it underlines second condition as "TS2538: Type 'undefined' cannot be used as an index type"

how else I can check property with possible zero value existence?

edit: modified my question as I pasted previous code version, added optional chaining as it is currently

edited Apr 20 '23 at 11:00

asked Apr 20 '23 at 10:20

ddominoo

1

What about `action.notificationKey !== undefined`? – Matija Sirk Apr 20 '23 at 10:21
you're looking for the [?? operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing) – nullptr Apr 20 '23 at 10:45
1

Could you please modify the question as this isn't optional chaining. – damonholden Apr 20 '23 at 10:48
@MatijaSirk yes, same result – ddominoo Apr 20 '23 at 11:01
Please provide a [mre] others can paste directly into their own IDEs to see your issue without having unrelated issues like undeclared variables. – jcalz Apr 20 '23 at 13:11

0 Answers0