How to produce 2 dimensional Array in Objective C - objective-c

Question

How do i produce a 2 dimensional NSMutable array as this:
Array:
=>[item1]=>[item1a,item1b,item1c...]
=>[item2]=>[item2a,item2b,item2c...]
...
=>[item10]=>[item10a,item10b,item10c...]
So far i've only been successful up to the [item1]=>[item1a,item1b,item1c...]
When i try to add more 2 dimensional array it keeps overriding the first row.

Answer 1

Create NSMutableArray and assign NSMutableArrays to it as its objects.
For example:
NSMutableArray * myBig2dArray = [[NSMutableArray alloc] init];
// first internal array
NSMutableArray * internalElement = [[[NSMutableArray alloc] init] autorelease];
[internalElement addObject:#"First - First"];
[internalElement addObject:#"First - Second"];
[myBig2dArray addObject:internalElement];
// second internal array
internalElement = [[[NSMutableArray alloc] init] autorelease];
[internalElement addObject:#"Second - First"];
[internalElement addObject:#"Second - Second"];
[myBig2dArray addObject:internalElement];

Answer 2

To make a 2 dimensional array you would make an array of arrays.
NSArray *2darray = [NSArray arrayWithObjects: [NSArray arrayWithObjects: #"one", #"two", nil], NSArray arrayWithObjects: #"one_2", #"two_2", nil]];
It gets very verbose but that is the way I know how to do this. An array of dictionaries may be better for your situation depending on what you need.

Answer 3

I wrote an NSMutableArray wrapper for easy use as a Two Dimensional array. It is available on github as CRL2DArray here . https://github.com/tGilani/CRL2DArray

Answer 4

First you to have set An NSMutableDictionary on .h file
#interface MSRCommonLogic : NSObject
{
NSMutableDictionary *twoDimensionArray;
}
then have to use following functions in .m file
- (void)setValuesToArray :(int)rows cols:(int) col value:(id)value
{
if(!twoDimensionArray)
{
twoDimensionArray =[[NSMutableDictionary alloc]init];
}
NSString *strKey=[NSString stringWithFormat:#"%dVs%d",rows,col];
[twoDimensionArray setObject:value forKey:strKey];
}
- (id)getValueFromArray :(int)rows cols:(int) col
{
NSString *strKey=[NSString stringWithFormat:#"%dVs%d",rows,col];
return [twoDimensionArray valueForKey:strKey];
}