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
let emptyArray = [Message]()