I have an NSArray full of NSDictionary objects, and each NSDictionary has a unique ID inside. I want to do lookups of particular dictionaries based on the ID, and get all the information for that dictionary in my own dictionary.
myArray contains:
[index 0] myDictionary object
name = apple,
weight = 1 pound,
number = 294,
[index 1] myDictionary object
name = pear,
weight = .5 pound,
number = 149,
[index 3] myDictionary object (etc...)
I want to get the name and weight for the second dictionary object (I won't know the index of the object... if there were only two dicts, I could just make a dictionary from [myArray objectAtIndex:1])
So, say I know the number 149. How would I be able to get the second myDictionary object out of myArray into a new NSDictionary?
As an alternative to Jacob's answer, you could also just ask the dictionary to find the object:
NSPredicate *finder = [NSPredicate predicateWithFormat:#"number = 149"];
NSDictionary *targetDictionary = [[array filteredArrayUsingPredicate:finder] lastObject];
You'd need to iterate through every NSDictionary object in your NSArray:
- (NSDictionary *) findDictByNumber:(NSInteger) num {
for(NSDictionary *dict in myArray) {
if([[dict objectForKey:#"number"] intValue] == num)
return [NSDictionary dictionaryWithObjectsAndKeys:[dict objectForKey:#"weight"], #"weight", [dict objectForKey:#"name"], #"name", nil];
}
return nil;
}
Related
I have 3 MutableArray's Named:
tvShows
tvNetworks
tvdbID
I need to sort them by the name of the tvShows.
But the need to stay linked.
So e.g.:
tvShows = Breaking Bad, House, Community;
tvNetworks = AMC, FOX, NBC;
tvdbID = 81189, 73255, 94571;
Needs To Become:
tvShows = Breaking Bad, Community, House;
tvNetworks = AMC, NBC, FOX;
tvdbID = 81189, 94571, 73255;
How would I do this? It's my first app so sorry if it's a realy easy question.
store them in an array of dictionaries then sort with an NSArray sort function: (below)
NSDictionary * dict1 = #{#"title":#"breaking bad",#"network":#"AMC",#"tvbdID":#(81189)};
NSDictionary * dict2 = #{#"title":#"house",#"network":#"FOX",#"tvbdID":#(73255)};
NSDictionary * dict3 = #{#"title":#"Community",#"network":#"NBC",#"tvbdID":#(94571)};
NSArray * array = #[dict1,dict2,dict3];
NSSortDescriptor * desc = [NSSortDescriptor sortDescriptorWithKey:#"title"ascending:YES selector:#selector(caseInsensitiveCompare:)];
NSArray * sortedArray = [array sortedArrayUsingDescriptors:#[desc]];
I would personally create a custom NSObject called TVShow, that has properties of showName, network, and tvbdID. This way, you only have one array of each show. Assuming your array is called myShows, you could do something like this:
[allShows sortUsingComparitor:^NSComparisonResult(id a, id b) {
NSString *firstName = [(TVShow*)a showName];
NSString *secondName = [(TVShow*)b showName];
return [firstName compare: secondName];
}];
That is, if you wanted to sort by show name. You can swap network for showName if you wanted to sort by network!
No idea what your end goal is, but you should probably create a TVShow class that has properties (i.e., instance variables) for "title," "network", and "dbid." Then you can instantiate three TVShow objects with their appropriate properties, put them in a mutable array, and use one of the sorting methods on NSMutableArray -- I'd probably choose sortUsingComparator:.
you can't do it with 3 independent arrays but maybe with 1 dictionary where the keys are tv shows and the value is a dictionary with 2 keys: tvNetworks & tvdbIDs
sample:
NSDictionary *data = #{#"Breaking Bad":#{#"tv" : #"AMC", #"tvdb": #(81189)},
#"House":#{#"tv" : #"FOX", #"tvdb": #(73255)},
#"Community":#{#"tv" : #"NBC", #"tvdb": #(94571)}};
NSArray *sortedShows = [data.allKeys sortedArrayUsingSelector:#selector(compare:)];
for (id show in sortedShows) {
NSLog(#"%# = %#", show, data[show]);
}
One of the easiest and most straightforward ways to do this would be to create one array of dictionaries, like this:
NSMutableArray *tvShowInfos = [NSMutableArray array];
for (NSInteger i = 0; i < tvShows.count; i++) {
NSDictionary *info = #{#"show": [tvShows objectAtIndex:i],
#"network": [tvNetworks objectAtIndex:i],
#"id": [tvdbIDs objectAtIndex:i]};
[tvShowInfos addObject:info];
}
You can then sort that array easily:
[tvShowInfos sortUsingDescriptors:#[ [[NSSortDescriptor alloc] initWithKey:#"show" ascending:YES] ]];
If you need an array that contains all networks, sorted by show title, you can then use valueForKey: on the array of dictionaries:
NSArray *networksSortedByShow = [tvShowInfos valueForKey:#"network"];
i have two arrays stored in dictionary:
array1=[[NSArray alloc]initWithObjects:a,b,c,d,e, nil];
array2=[[NSArray alloc]initWithObjects:1,2,3, nil];
NSDictionary * dic=[[NSDictionary alloc]initWithObjects:array1 forKeys:array2];
if i run i am getting error as:
-[NSDictionary initWithObjects:forKeys:]: count of objects (0) differs from count of keys (1)'
now i want to set dictionary only for a,b,c with keys: 1,2,3.
were as the arrays can't be edited
how can i do that
It does not make sense to add keys for nil values.
NSRange range = NSMakeRange(0, MIN(array1.count, array2.count));
NSDictionary * dic=[[NSDictionary alloc]initWithObjects:[array1 subarrayWithRange:range]
forKeys:[array2 subarrayWithRange:range]];
Use as :
array1=[[NSArray alloc]initWithObjects:a,b,c,d,e, nil];
array2=[[NSArray alloc]initWithObjects:1,2,3, nil];
// NSDictionary * dic=[[NSDictionary alloc]initWithObjects:array1 forKeys:array2];
NSMutableDictionary * dic=[NSMutableDictionary new];
for(int i=0 ; i< array2.count ; i++ ){
[dic setObject:array1[i] forKey:array2[i]];
}
Use NSMutableArray to work with the first array
remove d & e from it
From the Doc:
Neither a key nor a value can be nil; if you need to represent a null value in a dictionary, you should use NSNull.
A single key for the whole array is simple to set:
NSDictionary * dic=[[NSDictionary alloc]initWithObjects:array1 forKeys:#"Array"];
And if you want to add a key to each of the object in array, it goes like this:
NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
int key = 1;
for (NSString *str in array1) {
[dict setObject:str forKey:[NSString stringWithFormat:#"%d",key]];
key++;
}
Hope this helps!!!
I have an NSMutableArray that looks like this
{
"#active" = false;
"#name" = NAME1;
},
{
"#active" = false;
"#name" = NAME2;
}
Is there a way to convert this to an NSDictionary and then use objectForKey to get an array of the name objects? How else can I get these objects?
There is a even shorter form then this proposed by Hubert
NSArray *allNames = [array valueForKey:#"name"];
valueForKey: on NSArray returns a new array by sending valueForKey:givenKey to all it elements.
From the docs:
valueForKey:
Returns an array containing the results of invoking
valueForKey: using key on each of the array's objects.
- (id)valueForKey:(NSString *)key
Parameters
key The key to retrieve.
Return Value
The value of the retrieved key.
Discussion
The returned array contains NSNull elements for each object that returns nil.
Example:
NSArray *array = #[#{ #"active": #NO,#"name": #"Alice"},
#{ #"active": #NO,#"name": #"Bob"}];
NSLog(#"%#\n%#", array, [array valueForKey:#"name"]);
result:
(
{
active = 0;
name = Alice;
},
{
active = 0;
name = Bob;
}
)
(
Alice,
Bob
)
If you want to convert NSMutableArray to corresponding NSDictionary, just simply use mutableCopy
NSMutableArray *phone_list; //your Array
NSDictionary *dictionary = [[NSDictionary alloc] init];
dictionary = [phone_list mutableCopy];
This is an Array of Dictionary objects, so to get the values you would:
[[myArray objectAtIndex:0]valueForKey:#"name"]; //Replace index with the index you want and/or the key.
This is example one of the exmple get the emplyee list NSMutableArray and create NSMutableDictionary.......
NSMutableArray *emloyees = [[NSMutableArray alloc]initWithObjects:#"saman",#"Ruchira",#"Rukshan",#"ishan",#"Harsha",#"Ghihan",#"Lakmali",#"Dasuni", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in emloyees) {
NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
letterList = [dict objectForKey:firstLetter];
if (!letterList) {
letterList = [NSMutableArray array];
[dict setObject:letterList forKey:firstLetter];
}
[letterList addObject:word];
} NSLog(#"dic %#",dict);
yes you can
see this example:
NSDictionary *responseDictionary = [[request responseString] JSONValue];
NSMutableArray *dict = [responseDictionary objectForKey:#"data"];
NSDictionary *entry = [dict objectAtIndex:0];
NSString *num = [entry objectForKey:#"num"];
NSString *name = [entry objectForKey:#"name"];
NSString *score = [entry objectForKey:#"score"];
im sorry if i can't elaborate much because i am also working on something
but i hope that can help you. :)
No, guys.... the problem is that you are stepping on the KeyValue Mechanism in cocoa.
KeyValueCoding specifies that the #count symbol can be used in a keyPath....
myArray.#count
SOOOOOO.... just switch to the ObjectForKey and your ok!
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:#"theValue", #"#name", nil];
id kvoReturnedObject = [myDictionary valueForKey:#"#name"]; //WON'T WORK, the # symbol is special in the valueForKey
id dictionaryReturnedObject = [myDictionary objectForKey:#"#name"];
NSLog(#"object = %#", dictionaryReturnedObject);
for(Attribute* attribute in appDelegate.attributeArray) {
attribute = [appDelegate.attributeArray objectAtIndex:z];
attri = attribute.zName;
int y = 0;
for(Row* r in appDelegate.elementsArray) {
r = [appDelegate.elementsArray objectAtIndex:y];
NSString *ele = r.language;
if([attri isEqualToString:ele]) {
NSLog(#"=================+++++++++++++++++%# %#",attri, r.user);
[aaa insertObject:r atIndex:y]; //here i am adding the value to array
[dict setObject:aaa forKey:attri]; //here i am adding the array to dictionary
}
y++;
}
z++;
NSLog(#"============$$$$$$$$$$$$$$$$$$$$$$$++++++++++ %#",dict);
}
key in one array and the value in the another array and the value array is in object format.
I need to store the multi object for the single key. The attributeArray has the key value and the elementsArray has the object. For example the attributeArray might have the values
" English, French, German..."
and the elementsArray might have the object value
"<Row: 0x4b29d40>, <Row: 0x4b497a0>, <Row: 0x4e38940>, <Row: 0x4b2a070>, <Row: 0x4b29ab0>, <Row: 0x4b178a0> "
In the first value I need to store the two object and for second key I need to store 3 objects and for the third key in need to store last two objects in the dictionary.
For super-simplification you can use the following code:
NSArray *keys = ...;
NSArray *values = ...;
NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithObjects: values forKeys: keys];
Hope, this helps.
UPDATE:
to store multiple values for single key in the dictionary, just use NSArray / NSMutableArray as your object:
NSArray *keys = ...;
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for( id theKey in keys)
{
NSMutableArray *item = [NSMutableArray array];
[item addObject: ...];
[item addObject: ...];
...
[dict setObject: item forKey: theKey];
}
If you don't know all the values for the key from the beginning and need to add them one by one, you can use the following approach:
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for( /*some cycling condition here */)
{
id keyToUse = ...;
id valueToAdd = ...;
id foundArray = [dict objectForKey: keyToUse];
if ( nil == foundArray )
{
foundArray = [NSMutableArray array];
[dict setObject: foundArray forKey: keyToUse];
}
[foundArray addObject: valueToAdd];
}
To me it looks you are settings an array (aaa) with string (attri) as a key.
To set an array as a key for another array as an object. You can do this with the following appraoch.
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionaryWithCapacity:1];
NSArray *valueArray = [NSArray arrayWithObjects:#"v1", #"v2", nil];
NSArray *keyArray = [NSArray arrayWithObjects:#"k1",#"k2", nil];
[myDictionary setObject:valueArray forKey:keyArray];
NSLog(#"myDictionary: %#", myDictionary);
But you should review your code and provide a more brief explanation that what do you want to achieve and how are you taking an approach for this.
regards,
Arslan
I have and array of many strings.
I wan't to sort them into a dictionary, so all strings starting the same letter go into one array and then the array becomes the value for a key; the key would be the letter with which all the words in it's value's array begin.
Example
Key = "A" >> Value = "array = apple, animal, alphabet, abc ..."
Key = "B" >> Value = "array = bat, ball, banana ..."
How can I do that?
Thanks a lot in advance!
NSArray *list = [NSArray arrayWithObjects:#"apple, animal, bat, ball", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in list) {
NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
NSMutableArray *letterList = [dict objectForKey:firstLetter];
if (!letterList) {
letterList = [NSMutableArray array];
[dict setObject:letterList forKey:firstLetter];
}
[letterList addObject:word];
}
NSLog(#"%#", dict);
You can achieve what you want through the following steps:
Create an empty but mutable dictionary.
Get the first character.
If a key for that character does not exist, create it.
Add the word to the value of the key (should be an NSMutableArray).
Repeat step #2 for all keys.
Here is the Objective-C code for these steps. Note that I am assuming that you want the keys to be case insensitive.
// create our dummy dataset
NSArray * wordArray = [NSArray arrayWithObjects:#"Apple",
#"Pickle", #"Monkey", #"Taco",
#"arsenal", #"punch", #"twitch",
#"mushy", nil];
// setup a dictionary
NSMutableDictionary * wordDictionary = [[NSMutableDictionary alloc] init];
for (NSString * word in wordArray) {
// remove uppercaseString if you wish to keys case sensitive.
NSString * letter = [[word substringWithRange:NSMakeRange(0, 1)] uppercaseString];
NSMutableArray * array = [wordDictionary objectForKey:letter];
if (!array) {
// the key doesn't exist, so we will create it.
[wordDictionary setObject:(array = [NSMutableArray array]) forKey:letter];
}
[array addObject:word];
}
NSLog(#"Word dictionary: %#", wordDictionary);
Take a look at this topic, they solves almost the same problem as you — filtering NSArray into a new NSArray in objective-c Let me know if it does not help so I will write for you one more code sample.
Use this to sort the contents of array in alphabetical order, further you design to the requirement
[keywordListArr sortUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
I just wrote this sample. It looks simple and does what you need.
NSArray *names = [NSArray arrayWithObjects:#"Anna", #"Antony", #"Jack", #"John", #"Nikita", #"Mark", #"Matthew", nil];
NSString *alphabet = #"ABCDEFGHIJKLMNOPQRSTUWXYZ";
NSMutableDictionary *sortedNames = [NSMutableDictionary dictionary];
for(int characterIndex = 0; characterIndex < 25; characterIndex++) {
NSString *alphabetCharacter = [alphabet substringWithRange:NSMakeRange(characterIndex, 1)];
NSArray *filteredNames = [names filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"SELF BEGINSWITH[C] %#", alphabetCharacter]];
[sortedNames setObject:filteredNames forKey:alphabetCharacter];
}
//Just for testing purposes let's take a look into our sorted data
for(NSString *key in sortedNames) {
for(NSString *value in [sortedNames valueForKey:key]) {
NSLog(#"%#:%#", key, value);
}
}