Question

I have an NSArray of NSDictionary objects which I would like to be able to return a new array of NSDictionaries from, where every NSDictionary has “Area == North” (for example).

The closest example I have found so far is Using NSPredicate to filter an NSArray based on NSDictionary keys but this just returns the unique values for a given key, not the dictionary that has that key. Is there any way to perform a similar operation, and to return the entire dictionary?

Answer 1

Sounds easy enough:

NSArray *unfilteredDictionaries;  // however you get this...
NSMutableArray *filteredDictionaries = 
  [NSMutableArray arrayWithCapacity:[unfilteredDictionaries count]];
NSDictionary *dict;
for (dict in unfilteredDictionaries)
   if ([[dict valueForKey:@"Area"] isEqualToString:@"North"])
     [filteredDictionaries addObject:dict];

return filteredDictionaries;