Function produces expected type “String”, did you mean to call it with “()”

Question

let documentUrl: NSURL? = {
    return NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first
}

var test: String = {
             


        

Answer 1

You wrote this:

var test: String = {
    return "String"
}

That is not a computed property. You are initializing your variable test to a function body (an anonymous function, sometimes called a closure). That isn't what you mean to do. You want to call the function and set the variable test to the result. The parentheses make that happen; that is how you call a function. Thus:

var test: String = {
    return "String"
}()

Thus you define the function and call it, all in one move, and assign the result as the initial value of test.

If you wanted a computed property, you should have written it like this:

var test: String {
    return "String"
}

Notice there is no equal sign. A fuller form would be:

var test: String {
    get {
        return "String"
    }
}