for (NSString* key in xyz) { id value = xyz[key]; // do stuff } This works for every class that conforms to the NSFastEnumeration protocol (available on 10.5+ and iOS), though NSDictionary is one of the few collections which lets you enumerate keys instead of values. I suggest you read about fast enumeration in the … Read more
NSDictionary and the other collection classes are actually class clusters: several concrete subclasses classes masquerading under the interface of a single class: they all provide the same functionality (because they are subclasses of the same class — in NSDictionary’s case, this involves the three “primitive methods” -count, -objectForKey:, and -keyEnumerator), but have different internal workings … Read more
Finally we can solve this problem easily using JSONModel. This is the best method so far. JSONModel is a library that generically serialize/deserialize your object based on Class. You can even use non-nsobject based for property like int, short and float. It can also cater nested-complex JSON. Considering this JSON example: { “accounting” : [{ … Read more
You’re using NSDictionary. Unless you explicitly need it to be that type for some reason, I recommend using a Swift dictionary. You can pass a Swift dictionary to any function expecting NSDictionary without any extra work, because Dictionary<> and NSDictionary seamlessly bridge to each other. The advantage of the native Swift way is that the … Read more
No, they are not ordered. As long as you don’t add or remove any elements from the dictionary, they will remain in the same order, but as soon as you add or remove an element, the new order will be completely different. If you need the keys/values to be ordered, use an NSArray (or some … Read more
You can sort the keys and then create an NSMutableArray by iterating over them. NSArray *sortedKeys = [[dict allKeys] sortedArrayUsingSelector: @selector(compare:)]; NSMutableArray *sortedValues = [NSMutableArray array]; for (NSString *key in sortedKeys) [sortedValues addObject: [dict objectForKey: key]];
Johan is right — you’re not allowed to modify your app’s bundle. You have two good options for where to save your dictionary: the documents directory, which is backed up by iTunes when a user syncs their device; or the caches directory, which is not backed up. If you don’t need to have the data … Read more
Here’s the simplest way: NSDictionary* dict = …; [dict writeToFile:@”…” atomically:YES]; See the documentation for -writeToFile:atomically:.
The NSDictionary Method keysSortedByValueUsingComparator: should do the trick. You just need a method returning an NSComparisonResult that compares the object’s values. Your Dictionary is NSMutableDictionary * myDict; And your Array is NSArray *myArray; myArray = [myDict keysSortedByValueUsingComparator: ^(id obj1, id obj2) { if ([obj1 integerValue] > [obj2 integerValue]) { return (NSComparisonResult)NSOrderedDescending; } if ([obj1 integerValue] … Read more
Here is an example. Imagines you have an array of dictionnaries. Ecah dictionnary have 2 keys “name” & “dateOfBirth”. You can sort your array by “name” like this : // // Sort array by name // NSSortDescriptor *Sorter = [[NSSortDescriptor alloc] initWithKey:@”name” ascending:YES]; [myArray sortUsingDescriptors:[NSArray arrayWithObject:Sorter]]; [Sorter release]; Note that myArray is a NSMutableArray.