Cannot invoke '==' with argument

Question

I changed my core data model by adding an attribute to an entity. I've done a lightweight migration, but when I run the app I get a nil for some for the added attribute and thus a crash. I simply want to check for a nil and exclude the attribute if it is nil so as to avoid the crash. I've tried to do this with an if statement, but I get the error in the title. How can I get around this?

if comments == nil {
        cell.textLabel!.text! = "\(totalWorkTimeInHours) hours"
        cell.detailTextLabel!.text! = "Date: \(dateString)"

    } else {

        cell.textLabel!.text! = "\(totalWorkTimeInHours) hours"
        cell.detailTextLabel!.text! = "Date: \(dateString)\nComments: \(comments)"

    }

"Comments" is a string from Core Data. I know the error has something to do with the fact that I can't compare a string with nil, but I'm not sure how else to do it.

Thanks for the help!

Then perhaps your Core Data property is not an optional type? What type is the property--is it `String` or `String?` or `String!`? If it is the first one, then you really can't compare it to nil because Swift thinks it's required to have a value. — Matthew Quiros, Jan 05 '15 at 05:11
It was set to String I changed it to String! and I believe it's working how I want it to now. Thanks! — Leighton, Jan 05 '15 at 05:27

score 2 · Answer 1 · answered Jan 05 '15 at 05:07

2

var comments: String? = nil
if let comments = comments {
    println(comments)
} else {
    println("empty")
}

answered Jan 05 '15 at 05:07

Leo Dabus

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Cannot invoke '==' with argument

1 Answers1