Question

I’m trying to set error message if something is wrong, but I get

This class is not key value coding-compliant for the key NSLocalizedDescription

Here is the code I use

-(id)getMoneyFromAccount:(int) sum error:(NSError **)error
{
    if(self.balance - sum < 0)
    {
        NSDictionary *details = [NSDictionary dictionary];
        [details setValue:@"You don't have enough money" forKey:NSLocalizedDescriptionKey];
        *error = [NSError errorWithDomain:@"money" code:200 userInfo:details];
        return nil;
    }
    self.balance = self.balance - sum;
    return  [NSNumber numberWithInt:self.balance];
}

Answer 1

You are calling setValue:forKey: where you should be calling setObject:forKey:

[details setObject:@"You don't have enough money" forKey:NSLocalizedDescriptionKey];

In addition, you have to change from NSDictionary to NSMutableDictionary or set the values in the initializer:

NSDictionary *details = [NSDictionary
    dictionaryWithObject:@"You don’t…"
    forKey:NSLocalizedDescriptionKey];

The setValue:forKey: would work with a mutable dictionary, but it’s better to call setObject:forKey: directly.