CODEWITHSUNDEEP
swift
Daniele B
Daniele B

Reputation: 20412

Swift: how to set AnyObject to nil or equivalent

I have a very generic function which needs to return AnyObject:

func backgroundFunction(dm : DataManager) -> AnyObject {
    ...
}

however there are some cases where I would like to return an empty/null value

I thought about these two values:

but it doesn't seem to be allowed: Type 'AnyObject' does not conform to protocol 'NilLiteralConvertible'

but when I test if that AnyObject value is 0 with value != 0 I get this error: Binary operator '!=' cannot be applied to operands of type 'AnyObject' and 'nil'

Is there any solution?

Upvotes: 4

Views: 7150

Answers (2)

Arbitur
Arbitur

Reputation: 39081

Only an optional value can be set to nil or checked for nil. So you have to make your return type an optional.

func backgroundFunction(dm : DataManager) -> AnyObject? {
    ...
    return nil
}

Upvotes: 13

Daniele B
Daniele B

Reputation: 20412

I found the solution by returning an optional AnyObject:

func backgroundFunction(dm : DataManager) -> AnyObject? {

     if IHaveAValueToReturn {
         return TheValueToReturn
     }

     return nil
     // in case of optional AnyObject, you are allowed to return nil

}

Upvotes: 1

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