Fill NSMutableArray from another NsMutableArray - objective-c

Question

I have two classes indexViewController and flashCardQuestionViewController.
In the indexViewController i have table filled with an array.
Now i am getting some data from the database:
-(void)getMultipleChoiceAnswer
{
if(optionid!=nil)
[optionid removeAllObjects];
else
optionid = [[NSMutableArray alloc] init];
if(optionText!=nil)
[optionText removeAllObjects];
else
optionText = [[NSMutableArray alloc] init];
clsDatabase *clsDatabaseObject = [[clsDatabase alloc] init];
sqlite3_stmt *dataRows = [clsDatabaseObject getDataset:"select optionID,OptionText from flashCardMultipleAnswer where questionId=1"];
while(sqlite3_step(dataRows) == SQLITE_ROW)
{
[optionid addObject:[NSNumber numberWithInt:sqlite3_column_int(dataRows,0)]];
[optionText addObject:[NSString stringWithUTF8String:(char *)sqlite3_column_text(dataRows,1)]];
}
sqlite3_finalize(dataRows);
[clsDatabaseObject release];
}
and I am calling this method in the viewDidLoad method of the indexViewController.
Now I have another NSMutableArray in the flashCardQuestionViewController named listNoOfOptionsInQuestion.
I want to fill listNoOfOptionsInQuestion with objects from optionText array in indexViewController.
How can I do this?

Answer 1

There are a number of ways to copy arrays: you can either use -[NSArray copy] to get an immutable copy, or -[NSArray mutableCopy] for a mutable copy. Don't forget that copy adds a reference so you'll need a release or autorelease somewhere (if you're not using GC that is).
Alternatively, you can use -[NSMutableArray addObjectsFromArray:].
Given your example, it looks like you want to do something like this at the end:
[flashCardQuestionViewController setListNoOfOptionsInQuestion:optionText];
And then in FlashCardQuestionViewController, you want something like:
- (void)setListNoOfOptionsInQuestion:(NSArray *)options
{
if (options != listNoOfOptionsInQuestion) {
[listNoOfOptionsInQuestion release];
listNoOfOptionsInQuestion = [options mutableCopy];
}
}

Answer 2

Rahul,
Do you really need to have a completely different copy of the MutableArray in each object. Would it be possible to have both objects point to the same array? For instance:
ClassOne *one = [[ClassOne alloc] init];
ClassTwo *two = [[ClassTwo alloc] init];
// build mutable array mArray
// ...
one.objectArray = mArray;
two.objectArray = mArray;
Or do you need to make changes to the two arrays in different ways? The try this (as suggested by Chris above) :
ClassOne *one = [[ClassOne alloc] init];
ClassTwo *two = [[ClassTwo alloc] init];
// build mutable array mArray
// ...
one.objectArray = mArray;
two.objectArray = [mArray mutableCopy];
again, if this isn't what you need then you'll have to give us a more precise question or problem that we can identify.