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, e.g. 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)]