This is how I initialize my NSMutablearray. I copy the content of cityList into cityArray. Both are NSMutableArray. FYI, I declared the'cityArray' using extern.
cityArray = [[NSMutableArray alloc] init];
[cityArray addObjectsFromArray:cityList];
Then, in other method in another class, I tried to to add one more object into 'cityArray' This is how I do it. But it keep crashing when it run this line of code.
NSString *allCities = #"All Cities";
[[cityArray valueForKey:#"cityName"] addObject:allCities];
This is from the console '[__NSArrayI addObject:]: unrecognized selector sent to instance 0x6292de0''.
But if I test it with setvalue:forkey:, it works but that is not what I want. I want the new data to be added into the bottom of the list.
An NSArray doesn't implement valueForKey:. Your want either an NSDictionary or use objectAtIndex:.
Your second section of code should read:
NSString *allCities = #"All Cities";
[cityArray addObject:allCities];
Related
In my iphone project (ARC enabled) i have a nsmuatble array which contains some 5 managed objects (which are retrieved from core data ) and in some scenario i need to remove all the objects from that nsmutablearray
i have used following methods to remove objects but its crashing in both the cases with the crash log -[__NSArrayI removeObject:]: unrecognized selector sent to instance 0xa391640
if (surveys && [surveys count]>0)
{
[surveys removeAllObjects];
surveys = [[NSMutableArray alloc]init];
}
and also i tried
if (surveys && [surveys count]>0)
{
for(Survey *obj_Survey in surveys)
{
[surveys removeObject:obj_Survey];
}
surveys = [[NSMutableArray alloc]init];
}
can any one tell me how do i empty that array,, any suggestions would be appreciated, thanx in advance
The answer is very simple.
For First case.
Check the part where you have initialized your array, and check if somewhere through your code, if you have assigned an NSArray to your NSMutableArray object.
For second case.
You cannot remove objects from the array while you are enumerating through it. This will result in a crash saying array has mutated while enumerating
This:
[__NSArrayI removeObject:] : unrecognized selector sent to instance 0xa391640
indicates that your array "surveys" is NSArray (not-mutable). Are you sure you have initialized it properly? If you do it by an assignment like this
NSMutableArray* surveys = [someManagedObjectContext executeFetchRequest:request]
an array "surveys" will be of type NSArray because Core Data fetch requests return NSArrays.
The error message says it all,
[__NSArrayI removeObject:]: unrecognized selector
__NSArrayI is a code-word for an immutable array (NSArray), That means your surveys object is not NSMutablArray, but NSArray.
You cannot add or remove objects from NSArray.
Check your code. You have assigned NSArray to surveys or you have reinitialized it as NSArray.
Remove all the things that you are doing and simply do like this
[surveys removeAllObjects];
As from the error that you are getting so maybe that Array is not NSmutableArray just normal array so thats why you can not remove object from It and you try to do so and app got crash
check where you have initialised it if it is Mutable or not
so as I said remove all that thing and use simple removeAllObject
From the exception it's very evident that at some point you are assigning an immutable instance to your mutable array. From the comments I could make out that you were sorting surveys and sorted array was returning immutable array. Type casting will not do good for getting mutableCopy of an immutable object.
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor1,nil];
surveys = (NSMutableArray *) [[[NSMutableArray alloc]initWithArray:surveys ] sortedArrayUsingDescriptors:sortDescriptors];
Instead of it use
[surveys sortUsingDescriptors: #[sortDescriptor1]];
You might have initialised with Immutable Array.
Use the following Code:
NSMutableArray *newArray = [NSMutableArray arrayWithArray: oldArray];
I've looked everywhere for this, online, on stack overflow and cannot still work out what I'm doing wrong.
I'm trying to add an element to an existing NSMutableArray. But it crashes on line 4:
-[__NSArrayI addObject:]: unrecognized selector sent to instance 0x897b320
The code:
NSMutableArray *mystr = [[NSMutableArray alloc] init];
mystr = [NSArray arrayWithObjects:#"hello",#"world",#"etc",nil];
NSString *obj = #"hiagain";
[mystr addObject:obj];
What am I doing wrong? This is driving me crazy!!!
You array is not mutable!. Use NSMutableArray
mystr = [NSMutableArray arrayWithObjects:#"hello",#"world",#"etc",nil];
You get unrecognized selector since NSArray does not contain the addObject method
Your code should be:
NSMutableArray *mystr = [[NSMutableArray alloc] initWithObjects:#"hello",#"world",#"etc",nil];
NSString *obj = #"hiagain";
[mystr addObject:obj];
The second line you're reassigning an instance of NSArray rather of NSMutableArray to your mystr variable.
Try something like this:
NSMutableArray *mystr = [NSMutableArray arrayWithObjects:#"hello",#"world",#"etc",nil];
[mystr addObject:#"hiagain"]
You originally create mystr as a mutable array, but then assign it to a standard NSArray in the next line. Instead of calling "arrayWithObjects," add each item using "addObjects" or some other function that doesn't create a new immutable array.
Ahhhhh spotted it already
Line 2 should be:
[NSMutableArray arrayWithObjects:#"hello",#"world",#"etc",nil];
Sorry to waste your time with that!
I've got a question: I've got an NSMutableArray, which I pass on in multiple views. In one of the views, a value of an object inside that array (NSMutableDictionary) can be editted. I do that using the code:
NSMutableDictionary *tester = [[NSMutableDictionary alloc] initWithDictionary:selectedItem copyItems:YES];
NSMutableString *newLoc = [[NSMutableString alloc] initWithString:locationField.text];
[tester setValue:newLoc forKey:#"Location"];
[selectedList replaceObjectAtIndex:[selectedList indexOfObject:selectedItem] withObject:tester];
The problem I'm having with this, is replacing that object in selectedList. It gives the error *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayI replaceObjectAtIndex:withObject:]: unrecognized selector sent to instance 0xa631e30'
It works if I copy the new item in a copy-array of selectedList, and alloc selectedList with the new value again, but the other views are having problem finding that same list again in the array (new allocated location).
TL;DR version: how can I edit a value (through replacing?) inside an NSMutableArray? Why doesn't replaceObjectAtIndex work?
EDIT: It was immutable indeed. Still, the main question remains:
I've got:
NSMutableDictionary *tester = [[NSMutableDictionary alloc] initWithDictionary:geselecteerdItem copyItems:YES];
[geselecteerdItem setValue:nieuweLoc forKey:#"Location"];
[geselecteerdeLijst replaceObjectAtIndex:[geselecteerdeLijst indexOfObject:tester] withObject:geselecteerdItem];
When I'm using: [warningList replaceObjectAtIndex:[warningList indexOfObject:geselecteerdeLijst] withObject:keuzeLijst], it gives me an outofbounds error because the index of the array geselecteerdeLijst obviously changed inside warningList. Any idea's?
selectedList is an immutable array, which doesn't support any modifications. You can do something like this, though:
NSMutableArray *tmp = [NSMutableArray arrayWithArray: selectedList];
[tmp replaceObjectAtIndex:[selectedList indexOfObject:selectedItem] withObject:tester];
EDIT: To clarify, __NSArrayI is a concrete immutable subclass of NSArray, __NSArrayM is a mutable one. You should not rely on the private class names, but since they speak for themselves, you can at least know which is mutable and which is not.
There have been a few threads on this topic but none have been able to solve my problem. Essentially I am trying to add a custom object to an NSMutableArray and it doesn't seem to be adding. I don't get any errors but I get a warning saying that my array is an "unused variable" so it looks like it is not getting used. See code below. Any help is appreciated!
Here is the initialization in the app delegate (on run time it says this array is not being used):
NSMutableArray *organArray = [[NSMutableArray alloc] init];
Here is my object class organ.m (I am importing the app delegate, the rootviewcontroller and the organ.h file)
Organ *organObj = [[Organ alloc] initWithPrimaryKey:primaryKey];
organObj.organName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt,1)];
organObj.isDirty = NO;
[appDelegate.organArray addObject: organObj];
[organObj release];
I know the organObj.organName is getting the correct values from my sqlite db because I can output them to the console. They just don't seem to be getting added to the array and the fact that it says the array is not being used means something is wrong.
Thanks in advance
Just a guess but if organArray is intended to be a member of your app delegate, you are creating a new organArray when prefixing it with "NSMutableArray" so if I understand your code, change your app delegate to:
organArray = [[NSMutableArray alloc] init];
instead of:
NSMutableArray *organArray = [[NSMutableArray alloc] init];
I need to copy the contents of an NSArray to NSMutable array. In other words, I want to copy arrayCountryChoices to arraySearchResults. Any ideas????
//main data
NSArray *arrayCountryChoices;
//search results buffer
NSMutableArray *arraySearchResults;
//create data
arrayCountryChoices = [[NSArray alloc] initWithObjects:#"foo",#"bar",#"baz",nil];
//copy the original array to searchable array ->> THIS IS NOT WORKING AS EXPECTED
arraySearchResults = [[NSMutableArray alloc] arrayWithArray:arrayCountryChoices];
Thanks in advance.
it's either
[NSMutableArray arrayWithArray:anArray];
or
[[NSMutableArray alloc] initWithArray:anArray];
or
[anArray mutableCopy];
The code in your example doesn't work because you're calling arrayWithArray on an instance of NSMutableArray, but arrayWithArray is a class method.
As a general rule, initalization methods that start with init are instance methods, and those that start with the name of the class (array, etc.) are class methods. Class methods return autoreleased objects, while instance methods return retained objects.
You can also create empty mutable array and add objects to it using -addObjectsFromArray method
Please note that when using:
[NSMutableArray arrayWithArray:anArray];
or
[[NSMutableArray alloc] initWithArray:anArray];
you'll always get an array even if anArray was nil, but with:
[anArray mutableCopy];
you'll get nil if anArray is nil. So if you want to be sure that you actually get an array even if it may be empty, use one the former methods.
It's not working because arrayWithArray is a class method, not an instance method.
You can do [NSMutableArray arrayWithArray:arrayCountryChoices] to do what you need.
You could just call [arrayCountryChoices mutableCopy] to return a new mutable array with the contents of arrayCountryChoices.