How to sort custom data objects into an empty array by NSNumber property -Swift2 iOS

Question

I have a custom data object with a NSNumber property. How would I sort the messages from one array into another array using the NSNumber property?

I tried this but I get an error

Binary operator '<' cannot be applied to two 'NSNumber?' operands

emptyArray = messagesArray.sort{$0.time < $1.time}

Ascending or descending doesn't matter

class Message{
var toMessage: String?
var time: NSNumber?
}

var messagesArray[Message]()

let message1 = Message()
message1.toMessage = "Bonjour"
message1.time = 123

let message2 = Message()
message1.toMessage = "Hola"
message1.time = 456

let message3 = Message()
message1.toMessage = "Hello"
message1.time = 789

messagesArray.append(message1)
messagesArray.append(message2)
messagesArray.append(message3)

//I need to get the elements from messagesArray into emptyArray sorting by NSNumber time property
var emptyArray = [Message]()

Answer 1

我需要使用intValue

emptyArray = messagesArray.sort{$0.time.intValue < $1.time.intValue}