Question

I can’t figure out how to sort my array. It’s an array with dictionaries with dictionaries inside. So to get the startdate I would need to write

NSDictionary *object = [array objectAtIndex:0];
[[array objectForKey:@"DATE"]objectForKey:@"startDate"];

I want to sort the array, but because I need to sort it accordingly to the second dictionary I cant use this:

[array sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"startDate" ascending:YES]]];

I guess I just need to make some small adjustment, but I can’t figure out how.

Answer 1

First of all the line that you get your objects should be called on object instead of array. Furthermore you could use valueForKeyPath instead of objectForKey for nested dictionaries. Something like this:

[object valueForKeyPath:@"DATE.startDate"];

Now you just apply the same thing to your sort descriptor:

[array sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"DATE.startDate" ascending:YES]]];

Keep in mind though that sortUsingDescriptors:ascending: it’s a method that sorts in place and must be called on an NSMutableArray. If you just want a sorted copy of your array then use sortedArrayUsingDescriptors: method instead. I hope that this makes sense…