how can I sort NSMutableDictionary with keys value?

Question

I have a NSMutableDictionary with string keys and every key has its own array. I want to re-sort the dictionary with keys value alphabetically. How can I do this?

Tomaso

i have unsorted NSMutableDictionary with key value and i want to re-sort same NSMutableDictionary with key values alphabetically. Is that possible with NSMutableDictionary? – Tomaso

Answer 1

A dictionary is unsorted by definition.

For iterating over the keys in a specific order, you can sort an array containing the keys of the dictionary.

NSArray *keys = [theDictionary allKeys];
NSArray *sortedKeys = [keys sortedArrayUsingSelector:@selector(compareMethod:)];

There are several other sorted... methods, e.g. sorting with a NSComparator. Have a look here.

Hartley

Answer 2

Use this one

NSArray *myKeys = [Dict allKeys];
NSArray *sortedKeys = [myKeys sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
NSMutableArray *sortedValues = [[[NSMutableArray alloc] init] autorelease];

for(id key in sortedKeys) {
    id object = [Dict objectForKey:key];
    [sortedValues addObject:object];
}

Zackzackariah

I used this code to retrieve sorted dictionary but still get it unsorted `code NSMutableDictionary *dicProjectListSorted = [NSMutableDictionary dictionary]; NSArray *sortedKeys = [keys sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)]; NSMutableArray *sortedValues = [[[NSMutableArray alloc] init] autorelease]; for(id key in sortedKeys) { id object = [dicProjectList objectForKey:key]; [sortedValues addObject:object]; [dicProjectListSorted setObject:sortedValues forKey:key]; } – Tomaso

from this code u get shorted key value and thn by key value u get your data – Zackzackariah

sortedKeys getting correct as sorted but when i try to recreate dictionary (dicProjectListSorted) inside a loop i get it unsorted?? – Tomaso

Answer 3

NSDictionary *yourDictionary;
NSArray *sortedKeys = [yourDictionary.allKeys sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES]]];
NSArray *sortedValues = [yourDictionary objectsForKeys:sortedKeys notFoundMarker:@""];

Meghan

A worthy addition would be - that a Dictionary (whether mutable or immutable) maintains a hash table of its keys, and so - can never be really "sorted" - hence you MUST go through another collection object (here NSArray) which is ordered (maintains order of the items in the collection). – Harmsworth