How to create separate instance for NSMutableArray - iphone

Question

In my application I need to create a copy of NSMutableArray. Currently I am using mutableCopy method. But when I modify the copied array the original one is also modified. Please tell me How to create a new copy NSMutableArray.
Here is the code
delegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
self.mainImagesArray = [[NSMutableArray alloc]initWithArray:[delegate.arrayForCarCaptureImages mutableCopy]];
and here i am modifying
UIImage *filteredImage =[[[[self.mainImagesArray objectAtIndex:i]valueForKey:valueVheck] objectAtIndex:j] copy];
filteredImage =[filteredImage brightness:(1+sliderValue-0.5)];
[[[self.mainImagesArray objectAtIndex:i]valueForKey:valueVheck]removeObjectAtIndex:j];
[[[self.mainImagesArray objectAtIndex:i] valueForKey:valueVheck]insertObject:filteredImage atIndex:j];
After execution the arrayForCarCaptureImages also modified automatically.

Answer 1

You need to create a deep copy. From what I understand, you're creating a copy of the NSMutableArray itself without making copies of it's individual elements.
From what I see in the code you've written:
You're abusing the delegation pattern
Your code is not readable. Try passing it along to another developer, I bet you'll get slapped very fast :)
Here's an example of a classic case of deep copying:
NSArray *numbersArr = #[#1,#2,#3];
NSMutableArray *numbersArrCopy = [NSMutableArray array];
for (NSNumber *num in numbersArr) {
[numbersArrCopy addObject:[num copy]];
}
An easier approach:
NSArray *numbersArr = #[#1,#2,#3];
NSArray *numbersArrCopy = [[NSArray alloc] initWithArray:numbersArr copyItems:YES];
This is of course different than just:
NSArray *numbersArr = #[#1,#2,#3];
NSArray *numbersArrCopy = [numbersArr copy];

Answer 2

Have you tried:
NSArray *copiedArray = [[NSArray alloc] initWithArray:[otherArray copy]];

Answer 3

Try this code in your project:
NSMutableArray *array = [NSMutableArray arrayWithObjects:#"one", #"two", #"three", nil];
NSMutableArray *copiedArray = [array mutableCopy];
[array addObject:#"four"];
NSLog(#"copied %#", copiedArray);

Answer 4

MutableCopy will not perform deep copy. You have to do it manually as given,
NSMutableArray *arrayCopy = [NSMutableArray array];
for (id element in arraySource)
[arrayCopy addObject:[element mutableCopy]]; //or [arrayCopy addObject:[element copy]];

Answer 5

You code is hardly readable. See if this is working
delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
self.mainImagesArray = [[NSMutableArray alloc]initWithArray:delegate.mainImagesArray
copyItems:YES];
UIImage *filteredImage = self.mainImagesArray[i][valueVheck][j];
filteredImage = [filteredImage brightness:(1+sliderValue-0.5)];
[self.mainImagesArray[i][valueVheck]replaceObjectAtIndex:j
withObject:filteredImage];