Save string to the NSUserDefaults? - ios

Question

How to save a string into the NSUserDefaults?

Answer 1

NSString *valueToSave = #"someValue";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:#"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];
to get it back later
NSString *savedValue = [[NSUserDefaults standardUserDefaults]
stringForKey:#"preferenceName"];

Answer 2

more precisely
-(void)saveToUserDefaults:(NSString*)myString
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults) {
[standardUserDefaults setObject:myString forKey:#"timestamps"];
[standardUserDefaults synchronize];
}
}

Answer 3

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") {
}

Answer 4

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

Answer 5

Do not forget this statement because otherwise it may not always work:
[standardUserDefaults synchronize];

Answer 6

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"];

Answer 7

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

Answer 8

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";

Answer 9

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).

Answer 10

-(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]

Answer 11

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; }

Answer 12

For saving use this :
[[NSUserDefaults standardUserDefaults]setObject:#"YES" forKey:#"KTerminated"];
[[NSUserDefaults standardUserDefaults]synchronize];
For Retriveing use this :
[[[NSUserDefaults standardUserDefaults]stringForKey:#"KTerminated"] isEqualToString:#"YES"];

Answer 13

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
}

Answer 14

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!

Answer 15

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")

Answer 16

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)!
}