Creating an NSArray initialized with count N, all of the same object

Question

I want to create an NSArray with objects of the same value (say NSNumber all initialized to 1) but the count is based on another variable. There doesn't seem to be a way to do this with any of the intializers for NSArray except for one that deals with C-style array.

Any idea if there is a short way to do this?

This is what I am looking for:

NSArray *array = [[NSArray alloc] initWithObject:[NSNumber numberWithInt:0]
                                           count:anIntVariable];

NSNumber is just one example here, it could essentially be any NSObject.

Answer 1

The tightest code I've been able to write for this is:

id numbers[n];
for (int x = 0; x < n; ++x)
    numbers[x] = [NSNumber numberWithInt:0];
id array = [NSArray arrayWithObjects:numbers count:n];

This works because you can create runtime length determined C-arrays with C99 which Xcode uses by default.

If they are all the same value, you could also use memset (though the cast to int is naughty):

id numbers[n];
memset(numbers, (int)[NSNumber numberWithInt:0], n);
id array = [NSArray arrayWithObjects:numbers count:n];

If you know how many objects you need, then this code should work, though I haven't tested it:

id array = [NSArray arrayWithObjects:(id[5]){[NSNumber numberWithInt:0]} count:5];