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!!!
Related
I have a for loop that goes through a series of dictionaries in an array.
How can I consolidate all the dictionaries entries as it goes through the for loop into one NSMutableDictionary?
I tried addEntriesFromDictionary, but its not working. Thanks for your help.
for (int i=0; i<sections.count; i++){
formElements = [[sections objectAtIndex:i]objectForKey:#"Dictionary"];
}
NSMutableDictionary * mutableDict = [NSMutableDictionary dictionary];
for (NSDictionary * formElements in sections)
{
[mutableDict addEntriesFromDictionary:formElements];
}
This should work if It's correct that they don't share any keys.
you can add dictionary object like below.
NSMutableDictionary *mDict=[NSMutableDictionary dictionary];
[mDict addEntriesFromDictionary:DictObj];
NSMutableDictionary *mDict=[[NSMutableDictionary alloc]init];
NSMutableDictionary *mDict2=[[NSMutableDictionary alloc]init];
//later suppose you have 5 object in mDict and 2 object in mDict2. combine in this Way.
NSMutableArray *keys=[[NSMutableArray alloc]init];
NSMutableArray *obj=[[NSMutableArray alloc]init];
keys=[[mDict allKeys] mutableCopy];
obj=[[mDict allValues] mutableCopy];
[keys addObjectsFromArray:[mDict2 allKeys]];
[obj addObjectsFromArray:[mDict2 allValues]];
NSMutableDictionary *dict=[[NSMutableDictionary alloc]initWithObjects:obj forKeys:keys];
You can enumerate your dictionaries with -objectEnumerator or other methodfs of NSDictionary.
So inside your loop you enumerate your dictionary and add all objects an keys into one big dictionary.
Ok so I populate the array like this:
NSMutableArray *participants;
for(int i = 0; i < sizeofpm; i++){
NSDictionary *pmpart_dict = [pm_participants objectAtIndex:i];
NSString *pmpart_email = [pmpart_dict objectForKey:#"email"];
NSString *pmpart_email_extra = [#"pm" stringByAppendingString:pmpart_email];
[participants setValue:pmpart_email forKey:pmpart_email_extra];
NSLog(#"%#", participants);
}
sizeofpm is 1. that is using count. to get the number of values in the array. How can i store values to that array? It doesnt seem to be working. Thanks!
you need to alloc it first. Try to change the first line to:
NSMutableArray* participants = [[NSMutableArray alloc] init];
also using setValue:forKey: wont work with an NSMutableArray as an array has no key.
Try using [participants addObject:pmpart_email];.
You don't create the array, you just declare it.
NSMutableArray *participants = [NSMutableArray array];
After that, setValue:forKey: will not add objects to an array. You need addObject::
[participants addObject:pmpart_email];
There is no key.
You are assigning a value to an NSMutableArray *participants like how you assign values to an NSDictionary object. To assign values to NSMutableArray you can call - (void)addObject:(id)anObject
So, I as some of the other answer have stated, you're missing your initializer for participants. However, judging by your use of setValue:forKey:, and how you appear to be structuring your data, you're not looking for NSMutableArray, but instead NSMutableDictionary. Arrays are simply lists, whereas dictionaries maintain key-value relationships, which you appear to be attempting to leverage.
Try this:
// some classes provide shorthand for `alloc/init`, such as `dictionary`
NSMutableDictionary *participants = [NSMutableDictionary dictionary];
for(int i = 0; i < sizeofpm; i++){
NSDictionary *pmpart_dict = [pm_participants objectAtIndex:i];
NSString *pmpart_email = [pmpart_dict objectForKey:#"email"];
NSString *pmpart_email_extra = [#"pm" stringByAppendingString:pmpart_email];
[participants setValue:pmpart_email forKey:pmpart_email_extra];
NSLog(#"%#", participants);
}
This will give you a dictionary in the form of
{
pmpart_email_extra: pmpart_email
}
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);
}
}