NSMutableDictionary *expense_ArrContents = [[NSMutableDictionary alloc]init];
for (int i = 1; i<=4; i++) {
NSMutableArray *current_row = [NSMutableArray arrayWithObjects:#"payer_id",#"Expense_Type_id",#"Category_Id",#"SubCategory_Id",nil];
[expense_ArrContents setObject:current_row forKey: [NSNumber numberWithInt:i]];
}
NSArray *newArray = [expense_ArrContents allKeysForObject:#"payer_id"];
NSLog(#"%#",[newArray description]);
i want to get the list of key values containing the particular object which is in the array of values stored in nsmutabledictionary for a particular key.
In the line where you get all the keys ([expense_ArrContents allKeysForObject:#"payer_id"];) you actually get keys for an object that is not in any of the array's items. This #"player_id" is different object than the #"player_id" you added in current_row. In fact, maybe all of your rows have different #"player_id" objects (except if the compiler has made some optimization - maybe it threats that same string literal as one object instead of creating new object for each iteration).
Try creating an NSString object for the #"player_id" which you add to the current_row and then get all the keys for that same object:
NSString* playerId = #"player_id";
for(){
NSMutableArray *current_row = [NSMutableArray arrayWithObjects: playerId,...];
...
}
NSArray *newArray = [expense_ArrContents allKeysForObject:playerId];
Your NSArray *newArray = [expense_ArrContents allKeysForObject:#"payer_id"]; will not return any value because in expense_ArrContents there is no such key(#"payer_id"), instead there are keys like 1,2,3 etc.What is your requirement?Want to see what all keys are there in expense_ArrContents just log
NSArray*keys=[expense_ArrContents allKeys];
Try this :
NSMutableArray *array_key=[[NSMutableArray alloc]init];
for (NSString *key in expense_ArrContents) {
if ([[expense_ArrContents objectForKey:key] containsObject:#"payer_id"]) {
[array_key addObject:key];
}
}
Related
I have a simple UITableView, when users adds new rows, these will be added to the NSMutableDictionary. I can retrieve the values for a specific key.
NSArray *myArr = [myDictionary valueForKey:#"Food"];
This will show me all values for key food, this is an example of my NSLog:
(
burger,
pasta )
If I add more objects to myDictionary but for a different key, for example:
NSArray *drinks = [NSArray arrayWithObjects:#"cola",#"sprite",nil];
[myDictionary setObject:drinks forKey:#"Drink"];
I can't retrieve all values using the following code:
NSArray *allMenu = [myDictionary allValues];
It shows me the following NSLog:
(
(
burger,
past
),
(
cola,
sprite
) )
I don't know where is the problem. Why I can't get all values from NSDictionary to NSArray.
If I use the code:
NSArray *allMenu = [[myDictionary allValues] objectAtIndex:0];
will show me the Food values. If I change objectAtIndex to 1 will show me the Drink value.
I am not entirely sure what you are asking, if you are trying to print all of the values within an NSDictionary do the following:
//Gets an array of all keys within the dictionary
NSArray dictionaryKeys = [myDictionary allKeys];
for (NSString *key in dictionaryKeys)
{
//Prints this key
NSLog(#"Key = %#", key);
//Loops through the values for the aforementioned key
for (NSString *value in [myDictionary valueForKey:key])
{
//Prints individual values out of the NSArray for the key
NSLog(#"Value = %#", value);
}
}
You can do this in one line by flattening the returned 2-dimensional array by using key value coding (KVC). I found this in another answer, see the docs. In your case, it looks as follows:
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionary];
NSArray *food = [NSArray arrayWithObjects:#"burger",#"pasta",nil];
[myDictionary setObject:food forKey:#"Food"];
NSArray *drinks = [NSArray arrayWithObjects:#"cola",#"sprite",nil];
[myDictionary setObject:drinks forKey:#"Drink"];
NSArray *allMenue = [[myDictionary allValues] valueForKeyPath:#"#unionOfArrays.self"];
Try this Solution :
- (NSDictionary *) indexKeyedDictionaryFromArray:(NSArray *)array
{
id objectInstance;
NSUInteger indexKey = 0U;
for (objectInstance in myArr)
[mutableDictionary setObject:objectInstance forKey:[NSNumber numberWithUnsignedInt:indexKey++]];
return (NSDictionary *)[myDictionary autorelease];
}
I have an array which contains multiple Dictionaries each one with 3 keys (#"date", #"username", #"text").
What I want to check for, is whether the same user (#"username") exists in more than one dictionary in that Array. And, if she does, combine the text for those "duplicates" into one dictionary.
I have considered this answer to check for duplicates and this one
but I cannot figure out how to combine these two.
Jumping in here because although I think you should work on the code yourself first, I think Miro's answer is more complicated than the issue requires and though I like the idea of using predicates in Greg's answer, here's a 3rd solution that (1) wouldn't require you to change your data structure and (2) references the necessary loops...
The way I'd do it: Create an NSMutableArray then start adding the usernames in order. If the NSMutableArray already contains the username though, don't add another instance of the username, but instead merge the dictionary info.
ex.
// Note: I'm calling your array of user dictionaries userArray.
// Create a username array to store the usernames and check for duplicates
NSMutableArray *usernames = [[NSMutableArray alloc] init];
// Create a new userArray to store the updated dictionary info, merged
// entries et. al.
NSMutableArray *newUserArray = [[NSMutableArray alloc] init];
// Go through the array of user dictionaries
for (NSDictionary *userDict in userArray) {
// If the usernames array doesn't already contain the username,
// add it to both the usernames array and the newUserArray as is
if (![usernames containsObject:[userDict objectForKey:#"username"]]) {
[usernames addObject:[userDict objectForKey:#"username"]];
[newUserArray addObject:userDict];
}
// Otherwise, merge the userArray entries
else {
// Get a mutable copy of the dictionary entry at the first instance
// with this username
int indexOfFirstInstance = [usernames indexOfObject:[userDict objectForKey:#"username"]];
NSMutableDictionary *entry = [[newUserArray objectAtIndex:indexOfFirstInstance] mutableCopy];
// Then combine the "text" or whatever other values you wanted to combine
// by replacing the "text" value with the combined text.
// (I've done so with a comma, but you could also store the value in an array)
[entry setValue:[[entry objectForKey:#"text"] stringByAppendingString:[NSString stringWithFormat:#", %#", [userDict objectForKey:#"text"]]] forKey:#"text"];
// Then replace this newly merged dictionary with the one at the
// first instance
[newUserArray replaceObjectAtIndex:indexOfFirstInstance withObject:entry];
}
}
Maybe something like this [untested] example? Loop through, maintain a hash of existing items, and if a duplicate is found then combine with existing and remove.
NSMutableArray main; // this should exist, with content
NSMutableDictionary *hash = [[NSMutableDictionary alloc] init];
// loop through, backwards, as we're attempting to modify array in place (risky)
for(int i = [main count] - 1; i >= 0; i--){
// check for existing
if(hash[main[i][#"username"]] != nil){
int existingIdx = [hash[main[i][#"username"]] integerValue]; // get existing location
main[existingIdx][#"text"] = [main[existingIdx][#"text"] stringByAppendingString:main[i][#"text"]]; // "combine text" .. or however you'd like to
[main removeObjectAtIndex:i]; // remove duplicate
} else {
[hash setValue:[[NSNumber alloc] initWithInt:i] forKey:main[i][#"username"]]; // mark existance, with location
}
}
If you use NSMutableDictionary, NSMutableArray and NSMutableString you can do it with predicate like that:
NSMutableDictionary *d1 = [#{#"username": #"Greg", #"text" : [#"text 1" mutableCopy]} mutableCopy];
NSMutableDictionary *d2 = [#{#"username": #"Greg", #"text" : [#"text 2" mutableCopy]} mutableCopy];
NSMutableDictionary *d3 = [#{#"username": #"John", #"text" : [#"text 3" mutableCopy]} mutableCopy];
NSMutableArray *array = [#[d1, d2, d3] mutableCopy];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"username = %#", #"Greg"];
NSArray *filterArray = [array filteredArrayUsingPredicate:predicate];
NSMutableDictionary * firstDict = filterArray[0];
for (NSDictionary *d in filterArray)
{
if (firstDict != d)
{
[firstDict[#"text"] appendString:d[#"text"]];
[array removeObject:d];
}
}
We have an app that calls a SOAP web service and retrieves a long list of XML, which the app then parses into an NSArray of NSDictionary objects. The NSArray contains a list of Rental Apartment information, each of which is stored into an NSDictionary.
The entire list may contain 10 different types of Apartments (i.e. 2-room, 3-room), and we need to split the NSArray into smaller NSArrays based on Room-Type, which has the key "roomType" in the NSDictionary objects.
Currently our algorithm is
Use [NSArray valueForKeyPath:#"#distinctUnionofObjects.room-type"]
to obtain a list of unique room-type values.
Loop through the list of unique room-type values
For each unique room-type value, use NSPredicate to retrieve matching items from the Original list
Our code is below (renamed for clarity):
NSArray *arrOriginal = ... ...; // Contains the Parsed XML list
NSMutableArray *marrApartmentsByRoomType = [NSMutableArray arrayWithCapacity:10];
NSMutableArray *arrRoomTypes = [arrOriginal valueForKeyPath:#"distinctUnionOfObjects.roomType"];
for(NSString *strRoomType in arrRoomTypes) {
NSPredicate *predicateRoomType = [NSPredicate predicateWithFormat:#"roomType=%#", strRoomType];
NSArray *arrApartmentsThatMatchRoomType = [arrOriginal filteredArrayUsingPredicate:predicateRoomType]; // TAKES A LONG TIME EACH LOOP-ROUND
[marrApartmentsByRoomType addObject:arrApartmentsThatMatchRoomType];
}
However, step 3 is taking a long time as the original list may contain large amount (>100,000) of items. It seems that NSPredicate goes through the entire list for each key value. Is there a more efficient way of splitting a large NSArray into smaller NSArrays, based on NSDictionary keys?
If the order of your splited Arrays is not important, i have a solution for you:
NSArray *arrOriginal;
NSMutableDictionary *grouped = [[NSMutableDictionary alloc] initWithCapacity:arrOriginal.count];
for (NSDictionary *dict in arrOriginal) {
id key = [dict valueForKey:#"roomType"];
NSMutableArray *tmp = [grouped objectForKey:key];
if (tmp == nil) {
tmp = [[NSMutableArray alloc] init];
[grouped setObject:tmp forKey:key];
}
[tmp addObject:dict];
}
NSMutableArray *marrApartmentsByRoomType = [grouped allValues];
This is quite performant
- (NSDictionary *)groupObjectsInArray:(NSArray *)array byKey:(id <NSCopying> (^)(id item))keyForItemBlock
{
NSMutableDictionary *groupedItems = [NSMutableDictionary new];
for (id item in array) {
id <NSCopying> key = keyForItemBlock(item);
NSParameterAssert(key);
NSMutableArray *arrayForKey = groupedItems[key];
if (arrayForKey == nil) {
arrayForKey = [NSMutableArray new];
groupedItems[key] = arrayForKey;
}
[arrayForKey addObject:item];
}
return groupedItems;
}
Improving #Jonathan answer
Converting array to dictionary
Maintaining the same order as it was in original array
//only to a take unique keys. (key order should be maintained)
NSMutableArray *aMutableArray = [[NSMutableArray alloc]init];
NSMutableDictionary *dictFromArray = [NSMutableDictionary dictionary];
for (NSDictionary *eachDict in arrOriginal) {
//Collecting all unique key in order of initial array
NSString *eachKey = [eachDict objectForKey:#"roomType"];
if (![aMutableArray containsObject:eachKey]) {
[aMutableArray addObject:eachKey];
}
NSMutableArray *tmp = [grouped objectForKey:key];
tmp = [dictFromArray objectForKey:eachKey];
if (!tmp) {
tmp = [NSMutableArray array];
[dictFromArray setObject:tmp forKey:eachKey];
}
[tmp addObject:eachDict];
}
//NSLog(#"dictFromArray %#",dictFromArray);
//NSLog(#"Unique Keys :: %#",aMutableArray);
//Converting from dictionary to array again...
self.finalArray = [[NSMutableArray alloc]init];
for (NSString *uniqueKey in aMutableArray) {
NSDictionary *aUniqueKeyDict = #{#"groupKey":uniqueKey,#"featureValues":[dictFromArray objectForKey:uniqueKey]};
[self.finalArray addObject:aUniqueKeyDict];
}
Hope, It will help when client wants final array in same order as input array.
I have a UITableViewController that uses an array with values for every entry in the rows.
I want to set the values of that array by iterating over values read from a JSON file.
This is the new method I have created to read that data into an array and return it to my view controller. I don't know where to return the array, or how to really set it.
+(NSArray *)setDataToJson{
NSDictionary *infomation = [NSDictionary dictionaryWithContentsOfJSONString:#"Test.json"];
NSArray *test = [infomation valueForKey:#"Animals"];
for (int i = 0; i < test.count; i++) {
NSDictionary *info = [test objectAtIndex:i];
NSArray *array = [[NSArray alloc]initWithObjects:[Animal animalObj:[info valueForKey:#"AnimalName"]
location:[info valueForKey:#"ScientificName"] description:[info valueForKey:#"FirstDesc"] image:[UIImage imageNamed:#"cat.png"]], nil];
return array;
I know that my animalObj function worked when the data was local strings(#"Cat") and my dictionaryWithContentsOfJSONString works because I have tested, but I haven't used this function to set data to an array, only to UILabels, so this is where I am confused, on how to set this data into an array. But still use the For loop.
You want to use an instance of
NSMutableArray,
which will let you incrementally add elements to the array as you
iterate with the for-loop:
...
NSMutableArray *array = [NSMutableArray array];
for (int i = 0; i < test.count; i++) {
NSDictionary *info = [test objectAtIndex:i];
Animal *animal = [Animal animalObj:[info valueForKey:#"AnimalName"]
location:[info valueForKey:#"ScientificName"]
description:[info valueForKey:#"FirstDesc"]
image:[UIImage imageNamed:#"cat.png"]];
[array addObject:animal];
}
return array;
Because NSMutableArray is a subclass of NSArray, there's no need change the return type of your method.
I am familiar with getting a string count from a known array
int numberOfWords = [self.wordArray count];
but I have an unknown number of strings in an unknown number of arrays, all referenced by a dictionary. This works - good.
NSMutableDictionary *eqClasses = [[NSMutableDictionary alloc] init];
The arrays and strings are added at runtime (with help of this board):
NSMutableArray* array = [eqClasses objectForKey:wordPattern];
if(!array) {
// create new array and add to dictionary if wordPattern not found
array = [NSMutableArray array];
[eqClasses setObject:array forKey:wordPattern];
}
[array addObject:tempWordStr];
Now I need to iterate through the dictionary and get the array with the largest word count. Is there a way to scroll through all the arrays in the dictionary without using a key (I won't know all the word patterns as they are generated dynamically), AND once I find the array with the most words, get that array/value and key/wordpattern?
Well, there is a way to get all the keys within a dictionary:
NSArray *keyArray = [myDict allKeys];
And then you just go through the array and get the object for each key.
A fast enumeration should work nicely.
for (NSString *string in NSArray){
...
} //Assuming your keys are strings!
You can save each string to a temporary string, and when encountering a new string, compare to find the longer one. If it's longer, replace the old string with the longer one.
Hope this helped! ^_^
^_^
Okay, so now that you have an array full of all the keys in the dictionary,
you can iterate through the entire array and get the corresponding value (the string) for each key.
NSArray *keyArray = [myDict allKeys]; //This gets all the keys
NSString *tempString = #""; //This is the string you will save the longest string in. It gets updated when a longer string is found in the following loop.
for (NSString *string in keyArray){
NSString *stringFromCurrentKey = [myDict objectForKey:string];
if(stringFromCurrentKey.length > tempString.length){
tempString = stringFromCurrentKey;
}
} //By the end, you should be left with the longest string contained in tempString!
^_^ Hope this made sense and helped!
Try this code:
NSArray *largestArray = nil;
for (NSString *key in dictionary)
{
NSArray *array = [dictionary objectForKey:key];
if (array.count > largestArray.count) // largestArray.count is 0 if largestArray is nil
{
largestArray = array;
}
}