Question

I have written a class to help save and load data for the sake of persistence for my iPhone application but I have a problem with some NSUIntegers that I’m passing across.

Basically, I have the code to use pointers, but eventually it has to start out being an actual value right? So I get this error

warning: passing argument 1 of 'getSaveWithCampaign:andLevel:' makes pointer from integer without a cast

My code is laid out like so.

(Persistence is the name of the class)

NSDictionary *saveData = [Persistence getSaveWithCampaign:currentCampaign andLevel:[indexPath row]];

Here’s Persistence.m

#import "Persistence.h"


@implementation Persistence

+ (NSString *)dataFilePath
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    return [documentsDirectory stringByAppendingPathComponent:kSaveFilename];
}

+ (NSDictionary *)getSaveWithCampaign:(NSUInteger *)campaign andLevel:(NSUInteger *)level
{
    NSString *filePath = [self dataFilePath];

    if([[NSFileManager defaultManager] fileExistsAtPath:filePath])
    {
        NSDictionary *saveData = [[NSDictionary alloc] initWithContentsOfFile:filePath];

        NSString *campaignAndLevelKey = [self makeCampaign:campaign andLevelKey:level];

        NSDictionary *campaignAndLevelData = [saveData objectForKey:campaignAndLevelKey];

        [saveData release];

        return campaignAndLevelData;
    }
    else
    {
        return nil;
    }

}

+ (NSString *)makeCampaign:(NSUInteger *)campaign andLevelKey:(NSUInteger *)level
{
    return [[NSString stringWithFormat:@"%d - ", campaign+1] stringByAppendingString:[NSString stringWithFormat:@"%d", level+1]];
}   

@end

Answer 1

You should get rid of the * in ( NSUInteger *) in the getSaveWithCampaign method.

If you read the error message closely, it states that you are making a pointer (*) from an integer without a cast.

Your getSaveWithCampaign method should now have the following signature:

+ (NSDictionary *)getSaveWithCampaign:(NSUInteger)campaign andLevel:(NSUInteger)level

---

If, on the other hand, for some reason you do want to use pointers, you can pass in the NSUInteger prefixed with an ampersand (&) to pass in the address of the NSUInteger in memory.