nsarray

I have an NSArray of objects , which has a particular property called name (type NSString). I have a second NSArray of NSStrings which are names . I'd like to get an NSArray of all the objects whose .name property matches one of the names in the second NSArray. How do I go about this, fast and efficiently as this will be required quite often. With your current data structures, you can only do it in O(n^2) time by looping over the first array once for each member of the second array: NSMutableArray * array = [NSMutableArray array]; for (NSString * name in names) { for (MyObject * object in

What is an easy way to break an NSArray with 4000 objects in it into multiple arrays with 30 objects each? So right now I have an NSArray *stuff where [stuff count] = 4133. I want to make a new array that holds arrays of 30 objects. What is a good way to loop through, breaking *stuff into new 30-object arrays, and placing them inside of a larger array? Obviously the last array won't have 30 in it (it will have the remainder) but I need to handle that correctly. Make sense? Let me know if there is an efficient way to do this. samvermette Off the top of my head, something like (untested):

I am attempting to sort an NSArray that is populated with custom objects. Each object has a property startDateTime that is of type NSDate. The following code results in an array, sortedEventArray , populated but not sorted. Am I going about this the completely wrong way or am I just missing something small? NSSortDescriptor *dateDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"startDateTime" ascending:YES]; NSArray *sortDescriptors = [NSArray arrayWithObject:dateDescriptor]; NSArray *sortedEventArray = [nodeEventArray sortedArrayUsingDescriptors:sortDescriptors]; Are you sure that the

I need to serialize and deserialize objective-c objects into JSON to store in CouchDB. Do people have any example code for best practice for a general solution? I looked at a few JSON framework and they are stopped at the NSDictionary/NSArray level. i.e. A lot of framework will serialize and deserialize NSDictionary/NSArray into JSON. But I still have to do the work to convert NSDictionary into Objective-C objects. To make things more complex, my Object A can have reference to an NSArray/NSDictionary of Object Bs. My question is very similar to this question with addition of the collection

So I have an NSArray "myArray" with NSNumber s and NSString s. I need them in another UIView so i go like this: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { DetailViewController *details = [[DetailViewController alloc] initWithNibName:@"DetailView" bundle:nil]; details.subjectText = [[myArray objectAtIndex:indexPath.row] objectForKey:@"subject"]; The subjectText works. But how can I get the NSNumber s out of it? (I actually need them as strings...) I would convert a NSString out of a NSNumber like this: NSString *blah = [NSNumber intValue] . But

In a Cocoa Touch project, I need a specific class to have not only a single delegate object, but many of them. It looks like I should create an NSArray for these delegates; the problem is that NSArray would have all these delegates retained, which it shouldn't (by convention objects should not retain their delegates). Should I write my own array class to prevent retaining or are there simpler methods? Thank you! I found this bit of code awhile ago (can't remember who to attribute it to). It's quite ingenius, using a Category to allow the creation of a mutable array that does no retain/release