I need create an array to add objects with this format like a dictionary in Swift : ["key1": "value1", "key2": "value2"]
When I try to save it with NSUserDefaults
all is correct, but when read NSUserDefaults
with the key this crashes. What type of data does my var obj need?
let def = NSUserDefaults.standardUserDefaults()
var key = "keySave"
var element: AnyObject!
var array1: [AnyObject!] = []
array1.append(["key1": "val1", "key2": "val2"])
array1.append(["key1": "val1", "key2": "val2"])
//save
var savestring : [AnyObject!]
savestring = array1
var defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(savestring, forKey: key)
defaults.synchronize()
//read
var obj: [AnyObject!] = []
if(obj != nil){
print("size: ")
print(obj.count) //vary long value confused..
element = obj[0] //crash
print(element.objectForKey("key1"))
}
This question is related to
swift
nsuserdefaults
xcode6
Here is:
var array : [String] = ["One", "Two", "Three"]
let userDefault = UserDefaults.standard
// set
userDefault.set(array, forKey: "array")
// retrieve
if let fetchArray = userDefault.array(forKey: "array") as? [String] {
// code
}
Just to add on to what @Zaph says in the comments.
I have the same problem as you, as to know, the array of String
is not saved. Even though Apple bridges types such as String and NSString, I wasn't able to save an array of [String]
neither of [AnyObject]
.
However an array of [NSString]
works for me.
So your code could look like that :
var key = "keySave"
var array1: [NSString] = [NSString]()
array1.append("value 1")
array1.append("value 2")
//save
var defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(array1, forKey: key)
defaults.synchronize()
//read
if let testArray : AnyObject? = defaults.objectForKey(key) {
var readArray : [NSString] = testArray! as [NSString]
}
Note that I created an array of NSString and not a dictionary. I didn't check if it works with a dictionary, but probably you will have to define the things as [NSString : NSString]
to have it working.
EDIT
Re-reading your question and your title, you are talking of array of array
. I think that as long as you stay with NSString
, an array of array will work. However, if you think my answer is irrelevant, just let me know in the comments and I will remove it.
Here is an example of reading and writing a list of objects of type SNStock
that implements NSCoding
- we have an accessor for the entire list, watchlist
, and two methods to add and remove objects, that is addStock(stock: SNStock)
and removeStock(stock: SNStock)
.
import Foundation
class DWWatchlistController {
private let kNSUserDefaultsWatchlistKey: String = "dw_watchlist_key"
private let userDefaults: NSUserDefaults
private(set) var watchlist:[SNStock] {
get {
if let watchlistData : AnyObject = userDefaults.objectForKey(kNSUserDefaultsWatchlistKey) {
if let watchlist : AnyObject = NSKeyedUnarchiver.unarchiveObjectWithData(watchlistData as! NSData) {
return watchlist as! [SNStock]
}
}
return []
}
set(watchlist) {
let watchlistData = NSKeyedArchiver.archivedDataWithRootObject(watchlist)
userDefaults.setObject(watchlistData, forKey: kNSUserDefaultsWatchlistKey)
userDefaults.synchronize()
}
}
init() {
userDefaults = NSUserDefaults.standardUserDefaults()
}
func addStock(stock: SNStock) {
var watchlist = self.watchlist
watchlist.append(stock)
self.watchlist = watchlist
}
func removeStock(stock: SNStock) {
var watchlist = self.watchlist
if let index = find(watchlist, stock) {
watchlist.removeAtIndex(index)
self.watchlist = watchlist
}
}
}
Remember that your object needs to implement NSCoding
or else the encoding won't work. Here is what SNStock
looks like:
import Foundation
class SNStock: NSObject, NSCoding
{
let ticker: NSString
let name: NSString
init(ticker: NSString, name: NSString)
{
self.ticker = ticker
self.name = name
}
//MARK: NSCoding
required init(coder aDecoder: NSCoder) {
self.ticker = aDecoder.decodeObjectForKey("ticker") as! NSString
self.name = aDecoder.decodeObjectForKey("name") as! NSString
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(ticker, forKey: "ticker")
aCoder.encodeObject(name, forKey: "name")
}
//MARK: NSObjectProtocol
override func isEqual(object: AnyObject?) -> Bool {
if let object = object as? SNStock {
return self.ticker == object.ticker &&
self.name == object.name
} else {
return false
}
}
override var hash: Int {
return ticker.hashValue
}
}
Hope this helps!
Swift 4.0
Store:
let arrayFruit = ["Apple","Banana","Orange","Grapes","Watermelon"]
//store in user default
UserDefaults.standard.set(arrayFruit, forKey: "arrayFruit")
Fetch:
if let arr = UserDefaults.standard.array(forKey: "arrayFruit") as? [String]{
print(arr)
}
If you are working with Swift 5+ you have to use UserDefaults.standard.setValue(value, forKey: key)
and to get saved data you have to use UserDefaults.standard.dictionary(forKey: key)
.
Try this.
To get the data from the UserDefaults.
var defaults = NSUserDefaults.standardUserDefaults()
var dict : NSDictionary = ["key":"value"]
var array1: NSArray = dict.allValues // Create a dictionary and assign that to this array
defaults.setObject(array1, forkey : "MyKey")
var myarray : NSArray = defaults.objectForKey("MyKey") as NSArray
println(myarray)
Source: Stackoverflow.com