将NSArray转换为NSDictionary以进行分段

Question

I have this NSArray:

{name="LOBSTER",photo="prawn.jpg"},{name="COW", photo"cow_grass.png"},...so on

And I want to create section in the UITableView, so I need a dictionary like this:

{L=(name="Lobster";photo="prawn.jpg"),C=(name="COW"; photo="cow_grass.png"),...so on}

Could you please help me tell me how to do it? Thank you.

This is how I add my array:

animalsArray = [[NSMutableArray alloc] init];
      //Loop through our JsonDict
      long countArray = [[dataDict valueForKey:@"animal"]count];
      for (int i = 0; i < countArray ; i++)
         {
         NSString * cName = [[[dataDict valueForKey:@"animal"]objectAtIndex:i]valueForKey: @"name"];
         NSString * cPhoto = [[[dataDict valueForKey:@"animal"]objectAtIndex:i]valueForKey: @"photo"];

         [animalArray addObject:[[Animals alloc]initWithName:cName andPhoto:cPhoto]];

Answer 1

UPDATE

I now see that you want an object of type Animal instead of an NSDictionary . The line of code which was animal[@"name"] needs to be what ever accessor method to get the name. I updated my code to guess that you need animal.name .

Do you want a full index (A dictionary with all the values 'A'–'Z' even if most keys have an empty array)?

- (NSDictionary *)fullIndexOfAnimalsFromAnimals:(NSArray *)animals
{
    NSMutableDictionary *result = [NSMutableDictionary dictionary];

    // Create a key for each letter of the alphabet.
    for (char ch = 'A'; ch <= 'Z'; ++ch) {
        NSString *key = [NSString stringWithFormat:@"%c", ch];
        result[key] = [NSArray array];
    }

    // Add all the animals keyed by the first character of their name.
    for (Animal *animal in animals) {
        NSString *key = [animal.name substringToIndex:1] uppercaseString];
        result[key] = [result[key] arrayByAddingObject:animal];
    }

    return [result copy]; // NSMutableDictionary * to NSDictionary *
}

Do you want a partial index (A dictionary with only the keys that have values)?

- (NSDictionary *)partialIndexOfAnimalsFromAnimals:(NSArray *)animals
{
    NSMutableDictionary *result = [NSMutableDictionary dictionary];

    // Add all the animals keyed by the first character of their name.
    for (Animal *animal in animals) {
        NSString *key = [animal.name substringToIndex:1] uppercaseString];
        NSArray *value = result[key];
        if (value == nil) {
            result[key] = [NSArray arrayWithObject:animal]; // Create new array
        } else {
            result[key] = [value arrayByAddingObject:animal]; // Add to existing
        }
    }

    return [result copy]; // NSMutableDictionary * to NSDictionary *
}

---

As a second update, there is something odd.

[animalArray addObject:[[Animals alloc] initWithUser_id:cUser_id
                                                andName:cName
                                                 andNik:cNik
                                           andJob_title:cJob_title
                                               andPhone:cPhone
                                             andRoom_no:cRoom_no
                                               andPhoto:cPhoto]];

Is storying Animal * in animalArray , but the error message you have seems to indicate that NSMutuableArray * objects are being stored in animalArray .

Answer 2

Try below code..

NSMutableDictionary *finalResultDict=[NSMutableDictionary dictionary];

    for(NSDictionary *wildanimals in animalsarray)
    {

    NSString *key=[[wildanimals[@"name"] substringToIndex:1] uppercaseString];

    if([wildanimals[@"name"] hasPrefix:key])
    {
       [finalResultDict setValue: wildanimals forKey:key] ;
    }
    }

You can set number of sections by allKeysArray count as below

NSArray * allKeysArray = [finalResultDict allKeys];
NSLog(@"Count : %d", [finalResultDict count]);

Hope it helps you...!

Answer 3

Hope below is the code you are looking for.

NSArray *currentArray = ...

// New dictionary object to hold the grouped results.
NSMutableDictionary *dictionaryWithSections = [NSMutableDictionary dictionary];

for (NSDictionary *dictionary in currentArray) {
    NSString *section = [[[dictionary objectForKey:@"name"] substringToIndex:1] uppercaseString];

    // Check whether section already exits.
    if ([dictionaryWithSections objectForKey:section]) {
        [[dictionaryWithSections objectForKey:section] addObject:dictionary];
    } else {
        NSMutableArray *sectionData = [NSMutableArray arrayWithObject:dictionary];
        [dictionaryWithSections setObject:sectionData forKey:section];
    }
}

dictionaryWithSections is the new dictionary you get with grouping. [dictionaryWithSections allKeys] will return all the section titles you want. ie L, C.. etc.

Answer 4

Take Dictionary and set object for key

 NSMutableArray *arr;
NSMutableDictionary *dict=[[NSMutableDictionary alloc]init];
[dict setObject:arr forKey:@"L"];