Does UserDefaults.integer work on 32-bit platforms?

Question

Will the following code work on 32-bit platforms?

class Account {
  private static let UserIDKey = "AccountUserIDKey"
  class var userID: Int64? {
    get { Int64(UserDefaults.standard.integer(forKey: UserIDKey)) }
    set { UserDefaults.standard.set(newValue, forKey: UserIDKey) }
  }
}

Ie, will it work on 32-bit platforms if I store and retrieve an Int value that's greater than Int32.max into UserDefaults?

I'm wondering because I only see the UserDefaults instance method integer(forKey:). Why doesn't UserDefaults have an instance method like int64(forKey:)?

emrcftci · Answer 1 · 2020-03-07T05:24:35.590

You can save a number of simple variable types in the user defaults:

Booleans with Bool
integers with Int
floats with Float
doubles with Double
Strings with String
binary data with Data
dates with Date
URLs with the URL type
Collection types with Array and Dictionary

Internally the UserDefaults class can only store NSData, NSString, NSNumber, NSDate, NSArray and NSDictionary classes.

These are object types that can be saved in a property list.

An NSNumber is an NSObject that can contain the original C style numeric types, which even include the C/Objective-C style BOOL type (that stores YES or NO). Thankfully for us, these are also bridged to Swift, so for a Swift program, an NSNumber can automatically accept the following Swift types:

UInt
Int
Float
Double
Bool

Dmitry Popov's answer in Quora

Remember how you were taught in school how to add numbers like 38 and 54. You work with separate digits. You take rightmost digits, 8 and 4, add them, get the digit 2 in answer and 1 carried because of an overflow. You take the second digits, 3 and 5, add them to get 8 and add the carried 1 to get result 9, so the whole answer becomes 92. A 32-bit processor does exactly the same, but instead of decimal digits it's got 32-bit integers, algorithms are the same: work on two 32-bit parts of 64-bit number separately, deal with overflows by carrying from lower to higher word. This takes several 32-bit instructions and the compiler is responsible to encode them properly.

Save Int64 to UserDefaults

import Foundation

let defaults = UserDefaults.standart

//Define an 64bit integer with `Int64`
let myInteger: Int64 = 1000000000000000

//Save the integer to `UserDefaults`
defaults.set(myInteger, forKey: "myIntegerKey")

// Get the saved value from `UserDefaults`
guard let savedInteger = defaults.object(forKey: "myIntegerKey") as? Int64 else { return }

print("my 64bit integer is:", savedInteger)

Save 64bit Int to UserDefaults via converting to String

let myInteger: Int64 = 1000000000000000
let myString = String(myInteger)

//Save the `myString` to `UserDefaults`
UserDefaults.standard.set(myString, forKey: "myIntegerKey")


// Get the value from `UserDefaults`
let myString = UserDefaults.standard.string(forKey: "myIntegerKey")
let myInteger = Int64(myString!)

Resources

Is this an answer to "Does UserDefaults.integer work on 32-bit platforms?" and "Why doesn't UserDefaults have an instance method like int64(forKey:)?"? — Willeke, Mar 07 '20 at 09:00
Thank you, but as @Willeke pointed out, you did not answer my questions. — ma11hew28, Mar 09 '20 at 20:56

Does UserDefaults.integer work on 32-bit platforms?

1 Answers1