将字典中得key按照首字母排序

NSDictionary *dict = @{@"key":@2,@"anna":@1,@"hello":@3,@"ok":@4};

NSArray *keysArray = [dict allKeys];
NSArray *resultArray = [keysArray sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

return [obj1 compare:obj2 options:NSNumericSearch];
}];
for (NSString *value in resultArray) {

NSLog(@"[dict objectForKey:value] === %@",[dict objectForKey:value]);
}

2015-05-11 17:00:37.672 Category[2964:249821] [dict objectForKey:value] === 1
2015-05-11 17:00:37.673 Category[2964:249821] [dict objectForKey:value] === 3
2015-05-11 17:00:37.673 Category[2964:249821] [dict objectForKey:value] === 2
2015-05-11 17:00:37.673 Category[2964:249821] [dict objectForKey:value] === 4