How to unwrap an optional dictionary in swift?

Asked Mar 29 '21 at 20:04

Active Mar 29 '21 at 20:46

Viewed 78 times

I have a dictionary wrapped in an optional called optTest. After unwrapping the optional, it looks like this:

["fileName": "testName",
"fileSize": 10]

Given optTest, I am trying to retrieve fileName from this optional but having some trouble. I've tried this:

if let optTest = optTest but I am getting complaints from compiler. Anyone know how to do this?

Edit: This optional is part of the callback as defined here:

       public func someFunc(
            _ oldPath : String,
            resolver: @escaping RCTPromiseResolveBlock,
            rejector reject: @escaping RCTPromiseRejectBlock)

edited Mar 29 '21 at 20:46

asked Mar 29 '21 at 20:04

smolkitty

By hashmap you mean Dictionary right? – aheze Mar 29 '21 at 20:04
Also can you post code for the how `optTest` is declared (e.g. `var optTest: [String: Any]?`) – aheze Mar 29 '21 at 20:05
@aheze it is part of a callback. Something like this: `resolver([ "fileName": "testName", "fileSize": 10 ])` – smolkitty Mar 29 '21 at 20:07
Can you show the code for the function's callback? Like `func getStuff(resolver: @escaping ([String: Any]) -> Void)` or something. – aheze Mar 29 '21 at 20:17
1

@aheze ok I added it to question. Thanks for any help. – smolkitty Mar 29 '21 at 20:46
Np. But what is `RCTPromiseResolveBlock`? Option-click on it – aheze Mar 29 '21 at 20:47
This is what I found in the comments: `Block that bridge modules use to resolve the JS promise waiting for a result. Nil results are supported and are converted to JS's undefined value.` – smolkitty Mar 29 '21 at 20:48
Ok. What is your code for unwrapping `optTest`? – aheze Mar 29 '21 at 20:49
1

`if let fileName = optTest?["fileName"] { print(fileName)}` assuming optTest is optional – Joakim Danielson Mar 29 '21 at 20:50

How to unwrap an optional dictionary in swift?

0 Answers0