Create alphabetical NSDictionary from NSArray [closed] - ios

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Let's say I have an array that looks like this:
NSArray *array = #[#"Bear", #"Black Swan", #"Buffalo", #"Camel", #"Cockatoo", #"Dog", #"Donkey", #"Emu"]
How can I create following dictionary out of it?
NSDictionary *animals;
animals = #{#"B" : #[#"Bear", #"Black Swan", #"Buffalo"],
#"C" : #[#"Camel", #"Cockatoo"],
#"D" : #[#"Dog", #"Donkey"],
#"E" : #[#"Emu"]};

Answer 1

If I understand the question correctly you are trying to create a dictionary out of an array.
Try this:
NSArray *array = #[#"Bear", #"Black Swan", #"Buffalo", #"Camel", #"Cockatoo", #"Dog", #"Donkey", #"Emu"];
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
for (NSString *animal in array) {
NSString *firstLetter = [animal substringToIndex:1];
if (!dictionary[firstLetter]) {
dictionary[firstLetter] = [[NSMutableArray alloc] init];
}
[((NSMutableArray *)dictionary[firstLetter]) addObject:animal];
}
At the end the value of dictionary is:
dictionary = #{#"B" : #[#"Bear", #"Black Swan", #"Buffalo"],
#"C" : #[#"Camel", #"Cockatoo"],
#"D" : #[#"Dog", #"Donkey"],
#"E" : #[#"Emu"]};

Answer 2

I think you want to do this by :
NSMutableDictionary* animals =[NSMutableDictionary new];
NSArray* wAnimals =#[#"Whale", #"Whale Shark", #"Wombat"];
[animals setObject:wAnimals forKey:#"W"];

Answer 3

Please try this (Hope this will help you and i think you want like this)-
-(NSDictionary*)makeCustomDictionary:(NSString*)yourValue{
[array addObject:yourValue];
NSMutableArray *lettersKey = [NSMutableArray array];
NSMutableArray *values = [NSMutableArray array];
for (NSString *string in array) {
if (string.length > 0) {
NSString *letter = [string substringToIndex:1];
if (![lettersKey containsObject:letter]) {
[lettersKey addObject:letter];
NSString *stringToSearch = letter;
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF beginswith[c] %#",stringToSearch]; // if you need case sensitive search avoid '[c]' in the predicate
NSArray *results = [array filteredArrayUsingPredicate:predicate];
[values addObject:results];
}
}
}
return [NSDictionary dictionaryWithObjects:values forKeys:lettersKey];
}
- (IBAction)addNewValue:(id)sender {
NSDictionary *tempDic=[self makeCustomDictionary:txt.text];
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:tempDic
options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
error:&error];
if (! jsonData) {
NSLog(#"Got an error: %#", error);
} else {
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
NSLog(#"dictionary in json form - %# \n\n or dictionary simple- %#",jsonString,tempDic);
}
}
here array is global NSMutableArray initialize in viewDidLoad().
Output-
dictionary in json form -
{
"D" : ["Dog","Donkey"],
"B" : ["Bear","Black Swan","Buffalo"],
"G" : ["Giraffe"],
"E" : ["Emu"],
"C" : ["Camel","Cockatoo"]
}
or dictionary simple- {
B = (
Bear,
"Black Swan",
Buffalo
);
C = (
Camel,
Cockatoo
);
D = (
Dog,
Donkey
);
E = (
Emu
);
G = (
Giraffe
);
}