如何在物镜C中产生二维数组

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 NSMutableArray s 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];
        }