CODEWITHSUNDEEP
iosswift
KexAri
KexAri

Reputation: 3977

Trouble with basic callback blocks in Swift

brand new to Swift here. Trying to figure out how to do a very simple call back block from any asynchronous function I write.

For example:

 func downloadData(completion: (success: Bool) -> Void){

        let success: Bool
        //Some asynchronous task here
        success = true
        //Asynchronous task finished
        //Now I want to pass this back
        completion(success)

    }

I want to be able to call this function and get the value of the success variable in the block. However I'm getting an error "Missing argument label success in call". Don't understand what is going on here. Why would I need to include the argument label? Any pointers on this would be greatly appreciated!

Upvotes: 1

Views: 193

Answers (1)

vadian
vadian

Reputation: 285150

You have the choice:

Either you add the label in the call

completion(success: success)

or you omit the label in the declaration

func downloadData(completion: (Bool) -> Void){

The rule is: all declared labels must be passed.

Upvotes: 3

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