Using one variable as a reference to another in swift - ios

Question

I keep all of my users data in a User object and access it when I need it, as demonstrated in the example below on line 1. The inconvenience I encounter when using this method of data storing is when I need to edit these objects. Below, I have a Time object which belongs to the current user. Ideally, I would set the current user's times to a variable to make it more manageable, and then edit the times using that variable. The problem is, the time variable doesn't refer to the User.current().times[0] variable. Is there a way of using a variable essentially as a shortcut?
let time = User.current().times[0]
time.name = titleLabel.text
time.start = start
time.end = end
time.save()
User.current().times is of type [Time] which is a subclass of NSObject.
The declaration of the User class as requested with the current() function.
var this_user: User?
class User: NSObject {
var times = [Time]()
class func current() -> User {
if this_user == nil {
this_user = User()
}
return this_user!
}
}

Answer 1

Classes Are Reference Types
Unlike value types, reference types are not copied when they are assigned to a variable or constant, or when they are passed to a function. Rather than a copy, a reference to the same existing instance is used instead.
Just check User().current().times[0]. Is it a class or only a value? If you make an user object and holds that reference then you can get those.
For more Info see this.

Answer 2

Your code does work. The fault is in your testing procedure.
To prove this, I set up mock versions of your classes at the top level of a file, like this:
var this_user : User?
class Time : NSObject {
var start : String!
}
class User: NSObject {
var times = [Time]()
class func current() -> User {
if this_user == nil {
this_user = User()
}
return this_user!
}
}
Then, elsewhere, I ran this code:
let cur = User.current()
cur.times.append(Time()) // to give us a first Time in times
let time = User.current().times[0]
time.start = "Testing" // so let's see if we can write into it!
println(User.current().times[0].start) // Testing
This proves that when I set time.start it does reflect back into the Time that is in the times array of the current User. Therefore, I conclude that there is something wrong with the way you are testing your code. (Either that, or your description of your objects is inaccurate.)