CODEWITHSUNDEEP
iphonensmutablearraynsmutabledictionary
sujith1406
sujith1406

Reputation: 2822

crash on inserting an object into an array

In this code from an array i am selecting a dictionary,modifying it and saving back in another array .but i dont know why at the second last line of this code ie where i am inserting the dict it is crashing (message sent to deallocated instance).how can i fix this

        NSArray *array=[NSArray arrayWithContentsOfFile:plistPath];
        NSLog(@"array before %@",array);
        NSMutableArray *tempArray=[[NSMutableArray alloc]init];
        tempArray=(NSMutableArray*)array;
        NSMutableDictionary *dictToBeChanged=[[NSMutableDictionary alloc]init];
        dictToBeChanged=[tempArray objectAtIndex:indexPath.row];
        [dictToBeChanged setObject:[NSNumber numberWithBool:YES] forKey:@"isPaid"];
        [tempArray removeObjectAtIndex:indexPath.row];
        [tempArray insertObject:dictToBeChanged atIndex:indexPath.row];
        NSLog(@"array after %@",tempArray);

Upvotes: 0

Views: 123

Answers (4)

Dancreek
Dancreek

Reputation: 9544

You are looking at a memory management issue. Try this:

NSMutableArray *array = [NSMutableArray arrayWithContentsOfFile:plistPath];//Temp array is unecessary
NSMutableDictionary *dictToBeChanged; //No need to allocate a new instance

Not directly related but:

Both of your alloc [init] calls are unnecessary and causing leaks. Basically what you are doing is creating a new blank array with the allocation and and assigning it to a variable. Then you immediately assign your variable to another array, losing the reference to the blank array/dictionary you just created, which means it can't get released. If you are calling release later in your code it will cause trouble.

Upvotes: 1

André Morujão
André Morujão

Reputation: 7133

When you assign array to tempArray you don't make it mutable just because you cast it.

It's an NSArray, so you can't add/remove its objects.

Also, there are a few unneeded initializations (of tempArray and dictToBeChanged) since you're overwriting those variables with something else right after initializing (thus creating leaks).

What you need is probably something like this:

NSMutableArray *array = [NSMutableArray arrayWithContentsOfFile:plistPath];
NSMutableDictionary *dictToBeChanged = [[[array objectAtIndex:indexPath.row] mutableCopy] autorelease];
[dictToBeChanged setObject:[NSNumber numberWithBool:YES] forKey:@"isPaid"];
[array replaceObjectAtIndex:indexPath.row withObject:dictToBeChanged];

Note that this code doesn't do any validations on the contents of your plist.

Upvotes: 2

NIKHIL
NIKHIL

Reputation: 2719

try this

  NSMutableArray *temp;
temp=[temp arrayByAddingObjectsFromArray:(NSArray *)otherArray];

Upvotes: 1

Praveen S
Praveen S

Reputation: 10393

You may want to add the objects to tempArray as the temparray as follows:

[tempArray addObjectsFromArray:array];

Upvotes: 1

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