ios - Sort values of NSMutableDictionary alphabetically -

i have nsmutabledictionary integers key , nsstring values example:

key -- value

1 -- b

2 -- c

3 -- a

now want sort nsmutabledictionary alphabetically using values. want dictionary : key(3,1,2)->value(a,b,c). how can perform this?

from apple docs: https://developer.apple.com/library/mac/documentation/cocoa/conceptual/collections/articles/dictionaries.html#//apple_ref/doc/uid/20000134-sw4

sorting dictionary keys value:

nsdictionary *dict = [nsdictionary dictionarywithobjectsandkeys:     [nsnumber numberwithint:63], @"mathematics",     [nsnumber numberwithint:72], @"english",     [nsnumber numberwithint:55], @"history",     [nsnumber numberwithint:49], @"geography",     nil];  nsarray *sortedkeysarray =     [dict keyssortedbyvalueusingselector:@selector(compare:)]; // sortedkeysarray contains: geography, history, mathematics, english 

blocks ease custom sorting of dictionaries:

nsarray *blocksortedkeys = [dict keyssortedbyvalueusingcomparator: ^(id obj1, id obj2) {       if ([obj1 integervalue] > [obj2 integervalue]) {           return (nscomparisonresult)nsordereddescending;      }       if ([obj1 integervalue] < [obj2 integervalue]) {           return (nscomparisonresult)nsorderedascending;      }      return (nscomparisonresult)nsorderedsame; }];