mutating method sent to immutable object' - ios

Question

I am trying to add object to the array from a dictionary . In else part I am getting this error
mutating method sent to immutable object'
NSMutableDictionary *selectedDict = [NSMutableDictionary new];
[selectedDict setObject:editedLineItem forKey:#"Text"];
[selectedDict setObject:#"fa-check" forKey:#"IconClass"];
NSMutableArray *tagListDictionary = [NSMutableArray new];
[tagListDictionary addObject:selectedTagsArray];
LineItemsStorage *linestorage = [LineItemsStorage sharedManager];
if(![linestorage.packagesArray valueForKey:#"Id"])
{
[linestorage.selectedLineItemsAndTagsArray addObject:selectedDict];
}
else{ [[linestorage.packagesArray valueForKey:#"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]];
}
-[NSCFArray insertObject:atIndex:]: mutating method sent to immutable object'
*** First throw call stack:
(
0 CoreFoundation 0x00000001154a1d85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000114f15deb objc_exception_throw + 48
2 CoreFoundation 0x00000001154a1cbd +[NSException raise:format:] + 205
3 CoreFoundation 0x0000000115497b0a -[__NSCFArray insertObject:atIndex:] + 106
4 FlatPebble 0x000000010f276014 -[LineItemViewController okayAction] + 836
5 UIKit 0x0000000113809a8d -[UIApplication sendAction:to:from:forEvent:] + 92
6 UIKit 0x000000011397ce67 -[UIControl sendAction:to:forEvent:] + 67
7 UIKit 0x000000011397d143 -[UIControl _sendActionsForEvents:withEvent:] + 327
8 UIKit 0x000000011397c263 -[UIControl touchesEnded:withEvent:] + 601
9 UIKit 0x000000011387c99f -[UIWindow _sendTouchesForEvent:] + 835
10 UIKit 0x000000011387d6d4 -[UIWindow sendEvent:] + 865
11 UIKit 0x0000000113828dc6 -[UIApplication sendEvent:] + 263
12 UIKit 0x0000000113802553 _UIApplicationHandleEventQueue + 6660
13 CoreFoundation 0x00000001153c7301 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
14 CoreFoundation 0x00000001153bd22c __CFRunLoopDoSources0 + 556
15 CoreFoundation 0x00000001153bc6e3 __CFRunLoopRun + 867
16 CoreFoundation 0x00000001153bc0f8 CFRunLoopRunSpecific + 488
17 GraphicsServices 0x0000000116e5cad2 GSEventRunModal + 161
18 UIKit 0x0000000113807f09 UIApplicationMain + 171
19 *********** 0x000000010f348c2f main + 111
20 libdyld.dylib 0x0000000115d9992d start + 1
)

Answer 1

Use this code
NSMutableDictionary *selectedDict = [[NSMutableDictionary new]mutableCopy];
[selectedDict setObject:editedLineItem forKey:#"Text"];
[selectedDict setObject:#"fa-check" forKey:#"IconClass"];
NSMutableArray *tagListDictionary = [[NSMutableArray new]mutableCopy];
[tagListDictionary addObject:selectedTagsArray];
LineItemsStorage *linestorage = [LineItemsStorage sharedManager];
if(![linestorage.packagesArray valueForKey:#"Id"])
{
[linestorage.selectedLineItemsAndTagsArray addObject:selectedDict];
}
else{ [[linestorage.packagesArray valueForKey:#"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]];
}

Answer 2

Assuming your packagesArray contains an array containing one or more objects that have a LineItems property (that happens to also be an array); your problem is here:
[[linestorage.packagesArray valueForKey:#"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]]
Breaking it down it is equivalent to:
NSArray* packagesLineItems = [linestorage.packagesArray valueForKey:#"LineItems"];
NSMutableArray* selected = [NSMutableArray arrayWithObject:selectedDict];
[packagesLineItems addObject:selected];
So your problem is either the return type of valueForKey (when called on an array), or the action you're trying to do on it.