Swift NSUserDefaults not saving Dictionary?

I have the following test code:

  func testSaveDictionary() {
    let userDefaults = NSUserDefaults.standardUserDefaults()
    var jo = [
      "a" : "1.0",
      "b" : "2.0"
    ]

    let akey = "aKey"
    userDefaults.setObject(jo, forKey: akey)
    var isOk = userDefaults.synchronize()

    var data0 = userDefaults.dictionaryForKey(akey)
    println(data0)

  }

The output of println(data0) is nil.

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    5 Solutions Collect From Internet About “Swift NSUserDefaults not saving Dictionary?”

    Update for Swift 2, Xcode 7: As @atxe noticed, NSUserDefaults dictionaries are now mapped as [String, AnyObject]. This is a
    consequence of the Objective-C “lightweight generics” which allow
    to declare the Objective-C method as

    - (NSDictionary<NSString *,id> *)dictionaryForKey:(NSString *)defaultName
    

    (Default objects must be property lists and in particular the dictionary
    keys can only be strings.)

    On the other hand, a Swift dictionary is bridged automatically if possible, so the original code from the question works (again):

    let jo = [
        "a" : "1.0",
        "b" : "2.0"
    ]
    
    let akey = "aKey"
    // Swift 2:
    userDefaults.setObject(jo, forKey: akey)
    // Swift 3:
    userDefaults.set(jo, forKey: akey)
    

    Original answer for Swift 1.2:
    The user defaults can store NSDictionary objects. These are mapped to Swift
    as [NSObject : AnyObject]:

    var jo : [NSObject : AnyObject] = [
        "a" : "1.0",
        "b" : "2.0"
    ] 
    userDefaults.setObject(jo, forKey: akey)
    var isOk = userDefaults.synchronize()
    

    And note that dictionaryForKey() returns an optional, so you should check it
    for example with an optional assignment:

    if let data0 = userDefaults.dictionaryForKey(akey) {
        println(data0)
    } else {
        println("not set")
    }
    
    // Output: [b: 2.0, a: 1.0]
    

    You need to convert it into NSData first. Something like this:

    var data = NSKeyedArchiver.archivedDataWithRootObject(jo)
    var userDefaults = NSUserDefaults.standardUserDefaults()
    userDefaults.setObject(data, forKey:akey) 
    

    I faced with this problem yesterday and filed a radar: Cannot store Dictionary in NSUserDefaults in iOS8. This issue is related only to iOS 8. Also I described a workaround for this case: Workaround for saving dictionary in NSUserDefaults. Works like a charm.

    /// Save
    NSUserDefaults.standardUserDefaults().setObject(NSKeyedArchiver.archivedDataWithRootObject(object), forKey: key)
    
    /// Read
    var data = NSUserDefaults.standardUserDefaults().objectForKey(key) as NSData
    var object = NSKeyedUnarchiver.unarchiveObjectWithData(data) as [String: String]
    

    Follow this beautiful code below -> Swift 3

    public func setDict(dict: NSDictionary) {
        let data = NSKeyedArchiver.archivedData(withRootObject: dict)
        let userDefaults = UserDefaults.standard
        userDefaults.set(data, forKey:"keyHere")
    }
    
    
    public func getDict() -> NSDictionary {
        let data = UserDefaults.standard.object(forKey: "keyHere") as! NSData
        let object = NSKeyedUnarchiver.unarchiveObject(with: data as Data) as! NSDictionary
        return object;
    }
    

    //swift 4.0

    //for saving

        let userDefaults = UserDefaults.standard
        userDefaults.setValue(value, forKey: "Your_Key")
        userDefaults.synchronize()
    

    //for for retrieve

            let loadedCart = UserDefaults.standard.dictionary(forKey: "Your_Key")