Updating variable value from dictionary and best practice - swift

Question

As I progress into my Swift education, the time as come for me to ask for help about best practice and code optimization.
My app has become more and more complex every day and the current situation is as follows: I started using dictionaries and arguments to use a single function that can process a lot of different variables depending on the situation, which seems to be better practice than using 5 different functions that will do the same thing only with different variables.
I now have two files as follows:
Main1.swift:
class Main1 {
static var value1 : Int = 1
func updateValue(_ value: String) {
let dict : [String : Int] = ["value1": Main1.value1]
let dict1 = dict[value]
guard var value = dict1 else { return }
value = value + 1 // <- trying to update `static var value1`'s value from 1 to 2 here
print(value)
}
}
Main2.swift:
class Main2 {
func updateValue(_ value: String) {
let dict : [String : Int] = ["value1": Main1.value1] // <- thinking `value1` would now be 2
let dict1 = dict[value]
guard var value = dict1 else { return }
value = value + 1 // <- trying to get 3 here
print(value)
}
}
These classes are simplified versions of my code but the logic is the same: I am trying to use variables loaded from dictionaries and update their values to be used in another file and function:
Main1().updateValue("value1") //2
Main2().updateValue("value1") //2 <--- I need 3 here!
-> What exactly am I trying to achieve here?
To update the reference (static var value1 : Int = 1) value while accessing it through the convenience of a dictionary (or different method but you get the point about convenience).
In fact I am trying to do Main1.value1 = Main1.value1 + 1 while accessing Main1.value1 through a dictionary, which is impossible because I am not accessing the reference here.
I know this can't work, I have 3 different copies of value here but I don't how to update the variable value without using another global variable... I need your help to find a better logic.
I am open to any suggestion or thinking. I am not asking for code solution (which would be great anyway) but I'd love to have my education re-centered a little bit, I am starting to lose myself learning all by myself and the frustration comes from that I don't know what to be looking for anymore.

Answer 1

EDIT BASED ON COMMENTS
As per the comments below, here's a potential solution:
class Main1 {
static var dict: [String: Int] = ["value1": 1]
func updateValue(_ key: String) {
guard var value = dict[key] else { return }
value = value + 1
print(value)
dict[key] = value
}
}
ORIGINAL ANSWER
In Swift, [String : Int], String and Int are value types, as opposed to their Objective-C counterparts NSDictionary, NSString and NSNumber, which are reference types.
This means that when you do guard var value = dict1 else { return }, value is now a copy of what the dictionary contained, not a reference to that piece of data inside the dictionary.
So when you do value = value + 1 you're setting the new variables value, but not the contents of the dictionary.
Following your logic, you need to put value back into the dictionary, like this:
func updateValue(_ value: String) {
var dict : [String : Int] = ["value1": Main1.value1] // <- Change this to a var
let dict1 = dict[value]
guard var intValue = dict1 else { return }
intValue = intValue + 1 // <- trying to update `static var value1`'s value from 1 to 2 here
print(intValue)
dict[value] = intValue // <- ADD THIS
}