CODEWITHSUNDEEP
iosobjective-carraysmultidimensional-arraynsmutablearray
user1604476
user1604476

Reputation: 23

Multidimensional NSMutableArrays in Objective-C

I am very confused on how to use NSMutableArrays to store multiple dimensions of data.

I'm trying to store a car's make, model, year, and a description of a car (which is an NSString) in an array. The app plays a sound, loads the description, and shows a picture of the car. Originally, I was using a PLIST file to store this information. This was then loaded into a dictionary as the view loaded. However, I am no longer implementing the PLIST file, since it would be much easier for the program to automatically generate this data at runtime, based on the folders in the project.

The folders are broken down as follows: (Main Resources Folder) -> Makes -> Models -> Years -> Folder containing picture, .mp3, and file with description

For example: Cars -> Ford -> Mustang -> 1965 -> Pic, .mp3, description in file

    //Go to folder
    NSString * resourcePath = [[NSBundle mainBundle] resourcePath];
    NSString * documentsPath = [resourcePath stringByAppendingPathComponent:@"Cars"];
    NSError *error;
    //Load names of all makes in folder into memory
    NSArray * listOfMakes = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:documentsPath error:&error];

I then use multiple 'for' loops to iterate through this and all other folders, and to load everything else in to NSArrays.

However, I need one single array that is accessible program-wide. So, I am doing this within a singleton. I would like to add these arrays to an NSMutableArray, so that I can access it anywhere. I have viewed many other questions, like these: objective-c accessing arrays, Adding objects in Multidimensional NSMutableArray, How to add string objects to NSMutableArray, But am still very confused since these only cover up to three dimensions. Having multiple arrays of arrays is very confusing...

Any help would be very much appreciated.

Upvotes: 0

Views: 482

Answers (3)

Mihaela
Mihaela

Reputation: 2502

If you want a 2 dimensional array, than just one car array to it for each car:

[2dimArray addObject:@[make, model, year, description]];

Upvotes: 0

Fortinoh
Fortinoh

Reputation: 104

when it comes to multi-dimension...
I suggest you to use NSMutableDictionary or NSDictionary.

But the worst thing I see in your implementation is you are trying to load/hold the whole app data at once, Which will remain in memory till the app is not quit, since its store in singleton.

It will be better if you use CoreData and load only content which is required.

Upvotes: 2

Fahri Azimov
Fahri Azimov

Reputation: 11768

I don't know how you are building your app's logic, but if I were you, I would do something like this: 1. Make navigation based app. 2. In the first view show the list of models (load the list of models from Makes folder). 3. When particular model is selected, in the next view show the list of years. etc. And, no need to read all the contents of all folders in to the array. Good Luck!

Upvotes: 0

Related Questions