Save string to the NSUserDefaults?

Question

How to save a string into the NSUserDefaults?

Try this : http://jayprakashdubey.blogspot.in/2014/07/nsuserdefault-usage.html — Jayprakash Dubey, Jul 30 '14 at 10:26

score 468 · Accepted Answer · edited Apr 29 '14 at 18:52

468

NSString *valueToSave = @"someValue";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:@"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];

to get it back later

NSString *savedValue = [[NSUserDefaults standardUserDefaults]
    stringForKey:@"preferenceName"];

edited Apr 29 '14 at 18:52

tmanthey

4,547
6
35
42

answered Jun 19 '10 at 05:37

drawnonward

53,459
16
107
112

1

Is there any way to save this string base on specific date ? thanks but your code works as same as mine , I create a custom calendar app which user can write their notes in it , for example in 3 Feb user writes something and this text should be saved in 3 Feb , and when user move to the another days he/she could write something else accruing to thad day date – iOS.Lover Feb 02 '12 at 22:00
6

For some reason the saving part didn't work properly until I called the synchronize method. `NSString *valueToSave = @"someValue";[[NSUserDefaults standardUserDefaults]setObject:valueToSave forKey:@"preferenceName"]; [[NSUserDefaults standardUserDefaults]synchronize` – fs_tigre Feb 24 '14 at 02:07
5

[[NSUserDefaults standardUserDefaults] synchronize]; is getting deprecated – Juan Boero Mar 29 '16 at 17:53
As of iOS 12, calling `synchronize` is no longer needed: https://stackoverflow.com/a/57218546/12484 – Jon Schneider Aug 09 '20 at 22:07

score 51 · Answer 2 · answered Jun 19 '10 at 05:38

51

more precisely

-(void)saveToUserDefaults:(NSString*)myString
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) {
        [standardUserDefaults setObject:myString forKey:@"timestamps"];
        [standardUserDefaults synchronize];
    }
}

answered Jun 19 '10 at 05:38

Mihir Mehta

13,743
3
64
88

11

There is no need to perform the nil check for `standardUserDefaults` object. It is perfectly fine to send messages to nil in Objective-C. – jbrennan Jun 19 '10 at 06:29
12

But more importantly he included "synchronize" - NSUserDefaults is very erratic if you don't call this! – PostCodeism Nov 29 '10 at 19:48
1

standardUserDefaults synchronize fixed some strange bugs for me, thanks! – Scott Roepnack Dec 04 '12 at 18:00
1

The reference talks about the `synchronize` method: "use this method only if you cannot wait for the automatic synchronization (for example, if your application is about to exit)" - [NSUserDefaults Class Reference](https://developer.apple.com/library/ios/DOCUMENTATION/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html#//apple_ref/occ/instm/NSUserDefaults/synchronize) – eliocs Aug 30 '13 at 14:38
@jbrennan While your comment is technically correct, this answer is helpful in case you are writing something important and want to be sure it was saved successfully. Furthermore, in that regard, it would be good to test (rather than ignore) the return value of [`synchronize`](https://developer.apple.com/library/ios/documentation/cocoa/reference/foundation/classes/nsuserdefaults_class/reference/reference.html#//apple_ref/occ/instm/NSUserDefaults/synchronize). The doc says: YES if the data was saved successfully to disk, otherwise NO. – Basil Bourque Jun 02 '14 at 03:50

score 35 · Answer 3 · edited Sep 13 '16 at 16:48

35

Here's how to do the same with Swift;

var valueToSave = "someValue"
NSUserDefaults.standardUserDefaults().setObject(valueToSave, forKey: "preferenceName")

To get it back later;

if let savedValue = NSUserDefaults.standardUserDefaults().stringForKey("preferenceName") {
    // Do something with savedValue
}

In Swift 3.0

var valueToSave = "someValue"
UserDefaults.standard.set(valueToSave, forKey: "preferenceName")

if let savedValue = UserDefaults.standard.string(forKey: "preferenceName") {

}

edited Sep 13 '16 at 16:48

Ashok R

19,892
8
68
68

answered Apr 25 '15 at 15:48

Ε Г И І И О

11,199
1
48
63

Thanks, since the original question was for swift, +1 – Akshansh Thakur Jun 23 '16 at 09:04
I'm having trouble with my cynicism detector after lunch. The original question was asked in 2010. I therefore upvoted this since Swift is the way to go today. – Roy Falk Feb 15 '17 at 13:21

score 14 · Answer 4 · answered Jun 19 '10 at 06:04

Something like this:

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"];

Then to retrieve:

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *myString = [prefs stringForKey:@"keyToLookupString"];

You should really check out Apple's NSUserDefaults Class Reference and also maybe this tutorial: iPhone Programming Tutorial – Saving/Retrieving Data Using NSUserDefaults

score 13 · Answer 5 · answered Mar 05 '13 at 10:48

13

Do not forget this statement because otherwise it may not always work:

[standardUserDefaults synchronize];

answered Mar 05 '13 at 10:48

Walter Schurter

997
9
14

score 8 · Answer 6 · edited Apr 25 '15 at 20:23

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"];

// saving an NSInteger
[prefs setInteger:42 forKey:@"integerKey"];

// saving a Double
[prefs setDouble:3.1415 forKey:@"doubleKey"];

// saving a Float
[prefs setFloat:1.2345678 forKey:@"floatKey"];

// This is suggested to synch prefs, but is not needed (I didn't put it in my tut)
[prefs synchronize];

Retrieving

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *myString = [prefs stringForKey:@"keyToLookupString"];

// getting an NSInteger
NSInteger myInt = [prefs integerForKey:@"integerKey"];

// getting an Float
float myFloat = [prefs floatForKey:@"floatKey"];

score 7 · Answer 7 · answered Jun 19 '10 at 05:37

7

[[NSUserDefaults standardUserDefaults] setValue:aString forKey:aKey]

answered Jun 19 '10 at 05:37

Raviprakash

2,410
6
34
56

score 6 · Answer 8 · answered Aug 12 '13 at 11:28

6

A good practice is also to use a constant for the key to avoid bugs where you do not store and read with the same key

NSString* const TIME_STAMPS_KEY = @"TIME_STAMPS_KEY";

answered Aug 12 '13 at 11:28

Sunkas

9,542
6
62
102

Naresh · Answer 9 · 2022-01-18T14:52:51.597

In Swift5 and Xcode 10.2

//Save
UserDefaults.standard.set(true, forKey: "Key1") //Bool
UserDefaults.standard.set(1, forKey: "Key2")  //Integer
UserDefaults.standard.set("This is my string", forKey: "Key3") //String
UserDefaults.standard.synchronize()
        
//Retrive
UserDefaults.standard.bool(forKey: "Key1")
UserDefaults.standard.integer(forKey: "Key2")
UserDefaults.standard.string(forKey: "Key3")
            
//Remove
UserDefaults.standard.removeObject(forKey: "Key3")

Note: Save text data(means String, Array, Dictionary etc.) in UserDefaults.

Don't save images in UserDefaults, it's not recommended(Save images in local directory).

score 2 · Answer 10 · edited Aug 20 '15 at 02:51

-(void)saveToUserDefaults:(NSString*)string_to_store keys:(NSString *)key_for_the_String
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) {
        [standardUserDefaults setObject:string_to_store forKey:key_for_the_String];
        [standardUserDefaults synchronize];
    }
}

And call it by:

[self saveToUserDefaults:@"string_to_store" : @"key_for_the_string"];

Retrieve the string by using:

NSString * stored_string = [[NSUserDefaults standardUserDefaults] stringforkey:key_for_the_String]

Mithun R · Answer 11 · 2017-01-10T04:33:44.983

FirstView

    {
    NSMutableArray *array; }
- (void)viewDidLoad {
    [super viewDidLoad];
    array = [[NSMutableArray alloc]init];
    array = [[NSUserDefaults  standardUserDefaults]objectForKey:@"userlist"];

     NSLog(@"%lu",(unsigned long)array.count);
    if (array>0)
    {
        for (int i=0; i<array.count; i++)
        {
            NSDictionary *dict1 = @{@"Username":[[array valueForKey:@"Username"] objectAtIndex:i],@"Mobilenumber":[[array valueForKey:@"Mobilenumber"] objectAtIndex:i],@"Firstname":[[array valueForKey:@"Firstname"] objectAtIndex:i],@"Lastname":[[array valueForKey:@"Lastname"] objectAtIndex:i],@"dob":[[array valueForKey:@"dob"] objectAtIndex:i],@"image":[[array valueForKey:@"image"] objectAtIndex:i]};
            NSLog(@"%@",dict1);
            NSArray *array1 = [[NSArray alloc]initWithObjects:dict1, nil];
            [[NSUserDefaults standardUserDefaults] setObject:array1 forKey:@"UserList"];
        }

    }
     }

ImagePicker

     - (void)imagePickerController:(UIImagePickerController *)picker         didFinishPickingMediaWithInfo:(NSDictionary *)info {

    UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
    self.imaGe.image = chosenImage;

    [picker dismissViewControllerAnimated:YES completion:NULL];
     }

(IBAction)submitBton:(id)sender {

NSMutableArray *array2 = [[NSMutableArray alloc]initWithArray: 
[[NSUserDefaults standardUserDefaults]objectForKey:     
    @"userlist"]];                                

UIImage *ima = _imaGe.image;
NSData *imagedata = UIImageJPEGRepresentation(ima,100);

NSDictionary *dict =  @{@"Username":_userTxt.text,@"Lastname":_lastTxt.text,@"Firstname":_firstTxt.text,@"Mobilenumber":_mobTxt.text,@"dob":_dobTxt.text,@"image":imagedata};

   [array2 addObject:dict];
  [[NSUserDefaults standardUserDefaults]setObject:array2    
  forKey:@"userlist"];
   NSLog(@"%@",array2);

  [self performSegueWithIdentifier:@"second" sender:self];

 }

(IBAction)chooseImg:(id)sender {

UIImagePickerController *picker = [[UIImagePickerController
alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType =
UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:NULL];

}

second View { NSMutableArray *arr; }

- (void)viewDidLoad {
    [super viewDidLoad];

     arr =[[NSMutableArray alloc]init];
    arr = [[NSUserDefaults standardUserDefaults]objectForKey:@"userlist"]; }

#pragma mark- TableView DataSource

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1; }

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return arr.count; }

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *cellId = @"tablecell";
    TableViewCell *cell =[tableView dequeueReusableCellWithIdentifier:cellId];
    cell.userLbl.text =[[arr valueForKey:@"username"] objectAtIndex:indexPath.row];
    cell.ageLbl.text =[[arr valueForKey:@"dob"] objectAtIndex:indexPath.row];
    cell.profileImg.image =[UIImage imageNamed:[[arr valueForKey:@"image"] objectAtIndex:indexPath.row]];
    return cell; }

score 1 · Answer 12 · edited Mar 03 '16 at 20:41

1

For saving use this :

[[NSUserDefaults standardUserDefaults]setObject:@"YES" forKey:@"KTerminated"];
[[NSUserDefaults standardUserDefaults]synchronize];

For Retriveing use this :

[[[NSUserDefaults standardUserDefaults]stringForKey:@"KTerminated"] isEqualToString:@"YES"];

edited Mar 03 '16 at 20:41

Sangram Shivankar

3,535
3
26
38

answered Jan 07 '16 at 08:03

Subbu

62
6

Sapana Ranipa · Answer 13 · 2022-04-18T15:36:35.260

Here For Swift, I have created two functions which will be save and retrive value from the Preferences.

This will be help full for you.

// For saving object

static func setObject(value:AnyObject ,key:String)
{
    let pref = NSUserDefaults.standardUserDefaults()
    pref.setObject(value, forKey: key)
    pref.synchronize()
}

static func getObject(key:String) -> AnyObject
{
    let pref = NSUserDefaults.standardUserDefaults()
    return pref.objectForKey(key)!
}

score 1 · Answer 14 · answered Mar 26 '17 at 17:21

update for Swift 3

func setObject(value:AnyObject ,key:String)
{
    let pref = UserDefaults.standard
    pref.set(value, forKey: key)
    pref.synchronize()
}

func getObject(key:String) -> AnyObject
{
    let pref = UserDefaults.standard
    return pref.object(forKey: key)! as AnyObject
}

score 1 · Answer 15 · answered Jan 09 '18 at 07:31

In Swift 4.0.3 Xcode 9

============set  Data in UserDefaults =========

  UserDefaults.standard.set(userName, forKey: "userName")
  UserDefaults.standard.synchronize()

============Get Data in UserDefaults =========

  let userName = UserDefaults.standard.string(forKey: "userName")
  print(userName ?? "Gera")

  userNameTextField.text = ""+userName!

score 1 · Answer 16 · answered Feb 04 '21 at 22:40

1

Here Swift updated:

let userID = "BOB"

Declare userDefaults:

let defaults = UserDefaults.standard
defaults.setValue(userID, forKey: "userID")

And get it:

let userID = defaults.object(forKey: "userID")

answered Feb 04 '21 at 22:40

Damien

21
2

Save string to the NSUserDefaults?

16 Answers16

Linked

Related