I can't understand if this is get/set or closure in Swift

🎤 General Discussion Swift
1

I am using code where its like

let date: NSDate? = {
return nil
}()

what does it mean when you type () at end of the code.

Is that getter?

2

That’s a closure. You’ve basically written a long form of this:
let date: NSDate? = nil

The {} forms a closure around the instruction “return nil”. The () calls the closure, and Swift infers the closure’s arguments - it has none - from this; it infers the return type - NSDate? - from the declaration of the variable (date) you’re assigning the result of the closure to.

Getters and setters are about allowing enough access to your types (structs / classes etc.) to read useful information and allow useful configuration while hiding unnecessary detail and preventing you from accidentally making our types inconsistent. For example, count on an Array is a getter; you can call array.count and get a numerical value, but you can’t set the count of an array, and you wouldn’t want to.

Here’s one way you could write code to let someone get and set a value of type NSDate, so long as that date was before right now:

private var privateDate : NSDate = NSDate() // initialised to right now; hidden outside of the type.
var date : NSDate
{
  get { return privateDate }
  set {
    if newValue.compare(NSDate()) == NSOrderedAscending {
      privateDate = newValue
    }
  }
}
3

Thanks for the reply. It did actually help me a lot. Sorry for late reply.