Question

I want to declare a c array as an instance variable (e.g. int arr[256]) in the interface block of a Cocoa object. I know that @property doesn’t support c arrays but how to manually add the getter and setter for the c array and where should I alloc and release it?

Any input will be appreciated. I really don’t want to use NSMutableArray for accessing int values.

Answer 1

You can use structs to wrap up an array. This is probably the one exception that allows arrays to be copied by assignment. The benefit of this approach is that there is no need to explicitly allocate or free memory.

typedef struct
{
    int data[256];
} MyInts;


@interface MyClass : NSObject
{
    MyInts ints;
}
- (MyInts) ints;
- (void) setInts:(MyInts) someInts;
@end



@implementation MyClass

- (MyInts) ints
{
    return ints;
}

- (void) setInts:(MyInts) someInts
{
    ints = someInts;
}

@end


int main(void)
{
    MyInts ints = {{0}};
    ints.data[4] = 345;
    ints.data[5] = 123;
    ints.data[6] = 101;

    MyClass *someObj = [[MyClass alloc] init];

    [someObj setInts:ints]; // provide the ints to the object
    [someObj mutateTheInts]; // have object do something with them
    ints = [someObj ints]; // get them back

    return 0;
}