typeof any === 'object' leaves it any?

[celest pebble]

What is going on here folks?
https://www.typescriptlang.org/play?#code/GYVwdgxgLglg9mABMOcAUBDAXIjYCeAlIgN4BQiiMwiaU+ADgKZw0aIC8XiA5HAEYArJtB7FylShgqIA9LIB6AfhkBfMqqA

!ts

[orchid lava]

function foo(a: any) {
  if (typeof a === 'object') {
    a
//  ^? - (parameter) a: any
  }
}```

[celest pebble]

Why after checking if any is an object, it continues to stay any?

[calm nest]

Because any 😄

any & object is still any, which is why people say any is infectious and should be avoided almost always.

[celest pebble]

Omg

!ts

[orchid lava]

function foo(a: any) {
  if (typeof a === 'string') {
    a
//  ^? - (parameter) a: string
  }
}```

[celest pebble]

Why it is string then?

[calm nest]

Huh.

[celest pebble]

I cannot avoid using any, as I use it in a type guard like this:

function isTtsErrorResponse(a: any): a is TtsErrorResponse {
  return typeof a === 'object' && a != null && a?.hasOwnProperty('error_code') && a.hasOwnProperty('error_message');
}

[calm nest]

(Just don't use any 🤷)

Yes you can

Use unknown.

[celest pebble]

Ah, that, yes

Ok, but I still don't get why any doesn't work here

it works for strings but not of objects

[calm nest]

I'm not sure either, but at the same time I don't think people really care enough about any, because it's something you really shouldn't be using.

Anything any touches, basically has the effect of turning off TS.

[worldly blade]

  if (v === null) {
    v
  }

Doesn't narrow either. Seems like a bug to me. Or a quirk of how any is coded

As @calm nest says, use unknown