if i'm doing this
NSArray * myArray = [[NSArray alloc] init];
myArray = [[NSUserdefaults standardUserDefaults] objectForKey:#"array"];
[myArray release];
am i destroying value stored in NSUserDefaults for key #"array"? Is it still extractable or not already? Does [[NSUserdefaults standardUserDefaults] objectForKey:#"array"]; return pointer or value?
Your call to objectForKey is returning an autoreleased array.
Don't do the alloc/init or release thing around that. You'd be leaking and most likely crashing.
Just do:
NSArray * myArray = [[NSUserDefaults standardUserDefaults] objectForKey: #"array"];
am i destroying value stored in NSUserDefaults for key #"array"?
NO
Is it still extractable or not already?
Extractable
Does [[NSUserdefaults standardUserDefaults] objectForKey:#"array"]; return pointer or value?
Pointer. Returns pointer to object.
Now your code is incorrect. You can rewrite it like this:
NSArray * myArray = [[[NSUserdefaults standardUserDefaults] objectForKey:#"array"] retain];
....
[myArray release];
It sounds to me like you want to get rid of the value. What you are doing is making an array with the data from [[[NSUserdefaults standardUserDefaults] objectForKey:#"array"].
If you want to get the data and use it elsewhere:
NSArray * myArray = [[[NSUserDefaults standardUserDefaults] objectForKey:#"array"] retain];
// do stuff here
[myArray release];
just like beryllium said. Of course, you could have to set it first:
[[NSUserDefaults standardUserDefaults] setObject:anObject forKey:#"array"];
If you want to get rid of the data:
[[NSUserDefaults standardUserDefaults] removeObjectForKey:#"array"];
Because I honestly do not know what you are skiing, it is very hard to give you the answer you are looking for. Could you please clear it up a little?
Store array
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setObject:yourArray forKey:#"yourKey"];
[userDefaults synchronize];
Retrieve
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSArray *yourArr = [userDefaults objectForKey:#"yourKey"];
Related
I have an NSMutableArray. The array is storing NSMutableDictionary. The dictionary object is storing NSUserDefault values. These are slider values previously selected by user. Now I want that, when user move these sliders then new slider values must be saved in NSUserDefaults.
I'm using this method to add a value in the NSMutableArray
NSMutableArray *quarterValueArray = [[[NSUserDefaults standardUserDefaults]arrayForKey:#"QuarterValues"] mutableCopy];
if (!quarterValueArray)
{
NSMutableArray *aQuarterArray = [[NSMutableArray alloc] init];
for (int i = 0; i < 12; i++)
{
NSMutableDictionary *dict1 = [[[NSMutableDictionary alloc] init] mutableCopy];
[dict1 setObject:#"" forKey:#"quarterP"];
[dict1 setObject:#"" forKey:#"quartersliderValue"];
[dict1 setObject:#"" forKey:#"totalOfTheQuater"];
[aQuarterArray addObject:dict1];
}
[[NSUserDefaults standardUserDefaults] setObject:aQuarterArray forKey:#"QuarterValues"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
and then for storing slider values i am using this method in sliderviewCntroller
-(void)saveUserDefaultDataQuarter
{
NSMutableDictionary *quarter = [QuarterValueArray objectAtIndex:0];
[quarter setObject:totalQuarter1txt.text forKey:#"totalOfTheQuater"];
[quarter setObject:showQuartertxt.text forKey:#"quarterP"];
[quarter setObject:[NSString stringWithFormat:#"%d",(int)slider4.value]forKey:#"quartersliderValue"];
}
QuarterValueArray =[[[NSUserDefaults standardUserDefaults]arrayForKey:#"QuarterValues"]mutableCopy];
Why this code is crashing when the method is called second time? The crash log says:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFDictionary setObject:forKey:]: mutating method sent to immutable object'
Try this.
NSMutableArray *quarterValueArray = [[[NSUserDefaults standardUserDefaults]arrayForKey:#"QuarterValues"] mutableCopy];
if (!quarterValueArray)
{
NSMutableArray *aQuarterArray = [[NSMutableArray alloc] init];
for (int i = 0; i < 12; i++)
{
NSMutableDictionary *dict1 = [[[NSMutableDictionary alloc] init] mutableCopy];
[dict1 setObject:#"" forKey:#"quarterP"];
[dict1 setObject:#"" forKey:#"quartersliderValue"];
[dict1 setObject:#"" forKey:#"totalOfTheQuater"];
[aQuarterArray addObject:dict1];
}
[[NSUserDefaults standardUserDefaults] setValue:aQuarterArray forKey:#"QuarterValues"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
[self saveUserDefaultDataQuarter];
NSLog(#"%#",quarterValueArray);
and modify like this.
-(void)saveUserDefaultDataQuarter{
NSMutableArray*QuarterValueArray =[[[NSUserDefaults standardUserDefaults]arrayForKey:#"QuarterValues"]mutableCopy];
NSMutableDictionary *quarter = [QuarterValueArray objectAtIndex:0];
[quarter setValue:totalQuarter1txt.text forKey:#"totalOfTheQuater"];
[quarter setValue:showQuartertxt.text forKey:#"quarterP"];
[quarter setValue:[NSString stringWithFormat:#"%d",(int)slider4.value]forKey:#"quartersliderValue"]; }
UPDATE :I have used set value for setting the dictionary key values, as dictionary is already created when we are modifying values.
I am reading and writing an array to NSuserdefults in this way:
indexDelete = button.tag;
NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *dataRepresentingSavedArray = [currentDefaults objectForKey:#"save"];
if (dataRepresentingSavedArray != nil)
{
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
if (oldSavedArray != nil)
myIntegers = [[NSMutableArray alloc] initWithArray:oldSavedArray];
else
myIntegers = [[NSMutableArray alloc] init];
}
[myIntegers addObject:[NSNumber numberWithInteger:indexDelete]];
NSLog (#"Array myIntegers: %#", myIntegers);
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:myIntegers] forKey:#"save"];
Every thing works fine if I keep the line:
myIntegers = [[NSMutableArray alloc] init];
out of the brackets, because even if the data is there, it is not written or read correctly:
I get this error: -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL
What im I doing wrong??
Change this:
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:myIntegers] forKey:#"save"];
to
[[NSUserDefaults standardUserDefaults] setObject:myIntegers forKey:#"save"];
if myIntegers will not be mutated (changed) in the future. If it will be changed then use:
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithArray:myIntegers] forKey:#"save"];
The ability to save arrays and dictionaries in the user defaults is documented in the class description.
You never initialize your myIntegers. The first time you get the object for key save from your defaults you get a nil object (hence not entering the if closure and allocating the structure). After that you try to archive a nil object, which is probably the cause for the error you're getting.
Try moving the initialization of the array before this and only adding the objects from the previous saving if they exist:
myIntegers = [[NSMutableArray alloc] init];
NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *dataRepresentingSavedArray = [currentDefaults objectForKey:#"save"];
if (dataRepresentingSavedArray != nil)
{
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
if (oldSavedArray != nil)
[myIntegers addObjectsFromArray:oldSavedArray];
}
I have one alternative to do this is to save mutablearray in doc dir and then retrieve it:
// Get path to documents directory
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
if ([paths count] > 0)
{
// Path to save array data
NSString *arrayPath = [[paths objectAtIndex:0]
stringByAppendingPathComponent:#"array.out"];
// Write array
[yourMutableArray writeToFile:arrayPath atomically:YES];
// Read both back in new collections
NSMutableArray *arrayFromFile = [NSMutableArray arrayWithContentsOfFile:arrayPath];
for (NSString *element in arrayFromFile)
NSLog(#"Items: %#", element);
}
When setting NSUserDefaults, I was initially using this code to set the defaults...
NSMutableArray *array = [NSMutableArray arrayWithObjects: #"string1", #"string2", #"string3", nil];
[[NSUserDefaults standardUserDefaults] setObject:array forKey: #"preset1"];
[[NSUserDefaults standardUserDefaults] synchronize];
I've learned that I should be using this instead:
NSMutableArray *array = [NSMutableArray arrayWithObjects: #"string1", #"string2", #"string3", nil];
NSDictionary *appDefaults = [NSDictionary dictionaryWithObject:array forKey:#"preset1"];
[[NSUserDefaults standardUserDefaults] registerDefaults:appDefaults];
Now I'm having an issue manipulating the objects later on in array. Here is the code I use to add/remove strings from array. It worked fine when I was initially setting the defaults manually in my first example. Now, the objects will not remove from the array. I did notice when printing the array in LLDB debugger that array is now being stored as a NSCFArray when it was just an NSArray before.
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObjectsFromArray:[[NSUserDefaults standardUserDefaults] objectForKey:#"preset1"]];
NSArray *stringsToRemove = #[#"string1", #"string2" ];
for (NSUInteger i = 0; i < stringsToRemove.count; i++) {
[array removeObjectIdenticalTo:[stringsToRemove objectAtIndex:i]];
}
[[NSUserDefaults standardUserDefaults] setObject:array forKey: #"preset1"];
[[NSUserDefaults standardUserDefaults] synchronize];
This code works for me with your setup, after initializing the defaults the second way you described:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *array = [[NSMutableArray alloc] initWithArray: [defaults objectForKey:#"preset1"]];
NSArray *stringsToRemove = [NSArray arrayWithObjects:#"string1", #"string2", nil];
for (NSString *aString in stringsToRemove) {
[array removeObjectIdenticalTo:aString];
}
[defaults setObject:array forKey: #"preset1"];
[defaults synchronize];
Is the name of localized "jp" or "jap"
in
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:#"jp or jap"] forKey:#"AppleLanguages"];
You can sort your array as following
NSArray *sortedArray = [yourArray sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
localizedCaseInsensitiveCompare is method in NSString.
try with this,
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:#"ja_JP"] forKey:#"AppleLanguages"];
I saved an array using the following code:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:myArray];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"myArray"];
What is the code to load it back into memory?
Put this where you need to load it, should work. You'll get back an immutable NSData object.
NSData *data = [[NSUserDefaults standardUserDefaults] dataForKey:#"myArray"];