2d Byte array

Question

Hii all, m trying to make a 2d byte array . can any body give the code how to declare a NULL 2d byte array in Obj C for iPhone?

Thanks all.

Answer 1

Since objective-c is a strict superset of c, you could just use a pure c definition and it would work fine:

char** myMatrix = malloc(width*height);

You could also use an NSArray of NSArrays, but that's not a 2 dimensional array. It's a jagged array and considerably less easy to use than a plain byte array.

Another alternative is using an NSData/NSMutableData object. That is the Foundation way of working with byte arrays. See NSMutableData class reference for more information.

NSMutableData* data = [NSMutableData dataWithLength:1024]; // One kilobyte
void* dataPointer = [data mutableBytes]; // Get a pointer to the raw bytes

Answer 2

I'm cheating by doing this in C.

size_t width;
size_t height;
unsigned char *twoDimArray = calloc(width*height);