Storing Int64 in UserDefaults

Question

I define my dictionary like this:

var teamsData = Dictionary<String,Dictionary<String,Int64>>()

Then, I am trying to store it in userdefaults:

NSUserDefaults.standardUserDefaults().setObject(teamsData, forKey: "teamsData")

but it throws the error:

Type Dictionary<String,Dictionary<String,Int64>> does not conform to protocol 'Any Object'

Answer 1

A user default object can only be an instance (or a combination of instances) of NSData , NSString , NSNumber , NSDate , NSArray , or NSDictionary .

Some Swift types are automatically bridged to Foundation types, eg Int , UInt , Float , Double and Bool are bridged to NSNumber . So this could be saved in the user defaults:

var teamsData = Dictionary<String,Dictionary<String,Int>>()

On 64-bit architectures, Int is a 64-bit integer, but on 32-bit architectures, Int is a 32-bit integer.

The fixed-sized integer types such as Int64 are not automatically bridged to NSNumber . This was also observed in Swift - Cast Int64 to AnyObject for NSMutableArray . Therefore, to store 64-bit integers in the user defaults you have to use NSNumber explicitly:

var teamsData = Dictionary<String,Dictionary<String,NSNumber>>()

// Example how to add a 64-bit value:
let value : UInt64 = 123
teamsData["foo"] = ["bar" : NSNumber(unsignedLongLong: value)]

Answer 2

Martin's answer is no longer correct for Swift 3 since the set function is now type Any? instead of AnyObject? .

You can store an Int64 in UserDefaults like so:

import Foundation
let value: Int64 = 1000000000000000
UserDefaults.standard.set(value, forKey: "key")
if let value2 = UserDefaults.standard.object(forKey: "key") as? Int64 {
    // value2 is an Int64 with a value of 1000000000000000
    print(value2)
}

You can paste the above code into a Swift playground and try yourself.

Answer 3

Swift 4:

You can save int64 as string in UserDefaults

let value: Int64 = 1000000000000000
let stringValue = String(value)
UserDefaults.standard.set(stringValue, forKey: "int64String")

Like that you avoid Int truncation.

And then you can recover the original value:

let int64String = UserDefaults.standard.string(forKey: "int64String")
let originalValue = Int64(int64String!)

This allow you to compare it with other int64 values