CODEWITHSUNDEEP
iphoneobjective-carraysxcodedictionary
Joetjah
Joetjah

Reputation: 6132

Editting NSMutableDictionary in array

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?

Upvotes: 0

Views: 983

Answers (1)

Costique
Costique

Reputation: 23722

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.

Upvotes: 6

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