The title pretty much says it all, but just to clarify: I have an NSMutableDictonary containing several NSMutableArrays. What I would like to do is find any value that is present in multiple arrays (there will not be any duplicates in a single array) and return that value. Can someone please help? Thanks in advance!
Edit: For clarity's sake I will specify some of my variables:
linesMutableDictionary contains a list of Line objects (which are a custom NSObject subclass of mine)
pointsArray is an array inside each Line object and contains the values I am trying to search through.
Basically I am trying to find out which lines share common points (the purpose of my app is geometry based)
- (NSValue*)checkForDupes:(NSMutableDictionary*)dict {
NSMutableArray *derp = [NSMutableArray array];
for (NSString *key in [dict allKeys]) {
Line *temp = (Line*)[dict objectForKey:key];
for (NSValue *val in [temp pointsArray]) {
if ([derp containsObject:val])
return val;
}
[derp addObjectsFromArray:[temp pointsArray]];
}
return nil;
}
this should work
If by duplicates you mean returning YES to isEqual: you could first make an NSSet of all the elements (NSSet cannot, by definition, have duplicates):
NSMutableSet* allElements = [[NSMutableSet alloc] init];
for (NSArray* array in [dictionary allValues]) {
[allElements addObjectsFromArray:array];
}
Now you loop through the elements and check if they are in multiple arrays
NSMutableSet* allDuplicateElements = [[NSMutableSet alloc] init];
for (NSObject* element in allElements) {
NSUInteger count = 0;
for (NSArray* array in [dictionary allValues]) {
if ([array containsObject:element]) count++;
if (count > 1) {
[allDuplicateElements addObject:element];
break;
}
}
}
Then you have your duplicate elements and don't forget to release allElements and allDuplicateElements.
Related
There is an array in my app having multiple same values in it. I need to delete only one value at a time from array whether it has same more values in it.
Level1 Business,
Level2 Economy,
Level2 Economy,
Level1 Business
How this can be achieved, and main thing is that these values are dynamic these can be more or less also. Please guide for above.
Below is what i tried.
if([arr containsObject:[NSString stringWithFormat:#"%d",ind]]){
[arr removeObject:[NSString stringWithFormat:#"%d",ind]];
}
This thing removes all similar entries, not required. Thanks in advance.
try like this,
NSArray *array = [NSArray arrayWithObjects:#"Level1 Business", #"Level2 Economy", #"Level2 Economy", #"Level1 Business", nil];
NSMutableArray *mainarray=[[NSMutableArray alloc]initWithArray:array];
int n=[mainarray indexOfObject:#"Level2 Economy"];//it gives first occurence of the object in that array
if(n<[mainarray count]) // if the object not exist then it gives garbage value that's why here we have to take some condition
[mainarray removeObjectAtIndex:n];
NSLog(#"%#",mainarray);
O/P:-
(
"Level1 Business",
"Level2 Economy",
"Level1 Business"
)
As you say,
[array removeObject:#"SomeObject"];
removes all instances of where isEqual: returns YES. To remove only the first instance, you can use something like
NSUInteger index = [array indexOfObject:#"SomeObject"];
if(index != NSNotFound) {
[array removeObjectAtIndex:index];
}
Use [arr removeObjectAtIndex:yourIndex ] to remove your object at perticular postion at dynamic
Sample Code :
NSMutableArray *arr = [[NSMutableArray alloc]initWithObjects:#"hello",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",nil];
NSUInteger obj = [arr indexOfObject:#"hi"]; //Returns the lowest integer of the specified object
[arr removeObjectAtIndex:obj]; //removes the object from the array
NSLog(#"%#",arr);
In your Case :
if([arr containsObject:[NSString stringWithFormat:#"%d",ind]])
{
NSUInteger obj = [arr indexOfObject:[NSString stringWithFormat:#"%d",ind]]; //Returns the lowest integer of the specified object
[arr removeObjectAtIndex:obj];
}
Here your requirement is like definition of NSSet, which contains unique objects only.
But this will implies only if both the same value objects, are really in referring to same memory location as well.
If this is the case then and then, you can try code mentioned below:
// create set from an array
NSSet *telephoneSet = [NSSet setWithArray: myArray];
// create array from a set
NSMutableArray *array = [NSMutableArray arrayWithArray:[set allObjects]];
I don't know whether it will work for your requirement or not. But for that, it would be required to check the object equality level.
Still it might help you as an less line of code.
NSMutableArray *uniques= [[NSMutableArray alloc] init];
for (NSString *word in duplicateWordsArray){
if (!uniques.contains(word)){
[ uniques addObject:word];
}
}
I wrote this from my phone so it isn't formatted for code, but this will do it for you quickly and you'll have an array (uniquearray) that has unique words. Then you can use that one or set your original array = to unique array
NSArray *input = [NSArray arrayWithObjects:#"Level1 Business", #"Level2 Economy", #"Level2 Economy", #"Level1 Business", nil];
NSMutableArray *output = [[NSMutableArray alloc] init];
[output addObject:[input objectAtIndex:0]];
for(NSString *value in input) {
if(![output containsObject:value])
[output addObject:value];
}
I am attempting to use this array cleaning method, and there seems to be an error. I can't spot it, I know the array goes in with 3116 items, comes out with 3116 (and I know for a fact there are three duplicates.
Please advice, thanks!
-(NSArray*) removeDuplicates:(NSArray*)inputArray{
NSMutableArray *arrayToClean = [NSMutableArray arrayWithArray:inputArray];
for (int i =0; i<[arrayToClean count]; i++) {
for (int j=(i+1); j < [arrayToClean count]; j++) {
if ([[arrayToClean objectAtIndex:i] isEqual:[arrayToClean
objectAtIndex:j]]) {
[arrayToClean removeObjectAtIndex:j];
j--;
}
}
}
NSArray *arrayToReturn = [NSArray arrayWithArray:arrayToClean];
return arrayToReturn;
}
NSSet will make this a lot easier:
-(NSArray *)removeDuplicates:(NSArray *)inputArray {
NSSet *unique = [NSSet setWithArray:inputArray];
return [unique allObjects];
}
Please note that a set has no guaranteed order. If you need the objects in the array to be in a specific order then you should sort the resulting array as needed.
It may also be appropriate to use an NSSet instead of the original array, then you don't need to worry about duplicates at all. But this depends on the other needs of your array.
Hey You can use another alternative for this.You can use the NSSet here for this task.
NSSet declares the programmatic interface for static sets of distinct objects
You can use sets as an alternative to arrays when the order of elements isn’t important and performance in testing whether an object is contained in the set is a consideration—while arrays are ordered, testing for membership is slower than with sets.
You Just need To call below method.
-(NSArray *)removeDuplicates:(NSArray *)inputArray {
NSSet *finalData = [NSSet setWithArray:inputArray];
return [finalData allObjects];
}
If really face any problem in above way of cleaning ducplicates then you can try another Alterantive.
-(NSArray *)removeDuplicates:(NSArray *)inputArray {
NSMutableArray *inputArray1=[NSMutableArray arrayWithArray:inputArray];
NSMutableArray *finalARray=[[NSMutableArray alloc]init];
for (id obj in inputArray1)
{
if (![finalARray containsObject:obj])
{
[finalARray addObject: obj];
}
NSLog(#"new array is %#",finalARray);
}
return finalARray;
}
I hope it may help you ...
Here is a helper function I had in a previous project to do the exact same thing
- (NSMutableArray *)removeDuplicates:(NSMutableArray *)sortedArray{
NSMutableSet* valuesAdded = [NSMutableSet set];
NSMutableArray* filteredArray = [[NSMutableArray alloc] init];
NSString* object;
/* Iterate over the array checking if the value is a member of the set. If its not add it
* to the set and to the returning array. If the value is already a member, skip over it.
*/
for (object in sortedArray){
if (![valuesAdded member:object]){
[valuesAdded addObject:object];
[filteredArray addObject:object];
}
}
return filteredArray;
}
I am getting below response into the nsarray when I used the JSON parsing from my required URL but here I don't like to get 2,1,4,4,6,5,8,7,10,9,12 and 11 in single array I have to get total response into two arrays I mean one array set will consists 2,4,6,8,10 and other array set must be 3,5,7,9 and 11.
So how is the code for separation of single array response into two arrays in iPhone?
"(\n 2,\n 1\n)",
"(\n 4,\n 3\n)",
"(\n 6,\n 5\n)",
"(\n 8,\n 7\n)",
"(\n 10,\n 9\n)",
"(\n 12,\n 11\n)"
If you combine every number into one large array, you could feasibly test if each number is even or odd with a simple if-else in a for-in loop. Maybe like this:
-(NSArray*)parseJSONIntoArrays:(NSArray*)array {
NSMutableArray *evenNumbers = [[NSMutableArray alloc]init];
NSMutableArray *oddNumbers = [[NSMutableArray alloc]init];
for (NSNumber *number in array) {
if (([number intValue] %2) == 0) {
//even
[evenNumbers addObject:number];
}
else {
//odd
[oddNumbers addObject:number];
}
}
return [[NSArray alloc]initWithObjects:evenNumbers, oddNumbers, nil];
}
To split an array, you usually need to loop through all of the values and use an IF ELSE structure to decide which array to put the values in. Also, you need to use NSMutableArray instead of NSArray. Something like this:
NSMutableArray *evenNumbers = [NSMutableArray new];
NSMutableArray *oddNumbers = [NSMutableArray new];
for (NSNumber *value in myArray) {
if ([value intValue] % 2 == 0) {
[evenNumbers addObject:value];
} else {
[oddNumbers addObject:value];
}
}
I want to get the index of an object within the NSMutableArray of categories.
The category object has an attribute "category_title" and I want to be able to get the index by passing the value of category_title.
I have looked through the docs and can't find a simple way to go about this.
NSArray does not guarantee that you can only store one copy of a given object, so you have to make sure that you handle that yourself (or use NSOrderedSet).
That said, there are a couple approaches here. If your category objects implement isEqual: to match category_title, then you can just use -indexOfObject:.
If you can't do that (because the category objects use a different definition of equality), use -indexOfObjectPassingTest:. It takes a block in which you can do whatever test you want to define your "test" - in this case, testing category_title string equality.
Note that these are all declared for NSArray, so you won't see them if you are only looking at the NSMutableArray header/documentation.
EDIT: Code sample. This assumes objects of class CASCategory with an NSString property categoryTitle (I can't bring myself to put underscores in an ivar name :-):
CASCategory *cat1 = [[CASCategory alloc] init];
[cat1 setCategoryTitle:#"foo"];
CASCategory *cat2 = [[CASCategory alloc] init];
[cat2 setCategoryTitle:#"bar"];
CASCategory *cat3 = [[CASCategory alloc] init];
[cat3 setCategoryTitle:#"baz"];
NSMutableArray *array = [NSMutableArray arrayWithObjects:cat1, cat2, cat3, nil];
[cat1 release];
[cat2 release];
[cat3 release];
NSUInteger barIndex = [array indexOfObjectPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
if ([[(CASCategory *)obj categoryTitle] isEqualToString:#"bar"]) {
*stop = YES;
return YES;
}
return NO;
}];
if (barIndex != NSNotFound) {
NSLog(#"The title of category at index %lu is %#", barIndex, [[array objectAtIndex:barIndex] categoryTitle]);
}
else {
NSLog(#"Not found");
}
Not sure that I understand the question but something like this might work (assuming the Mutable Array contains objects of Class "Category"):
int indx;
bool chk;
for (Category *aCategory in theArray)
{
chk = ([[aCategory category_title] isEqualToString:#"valOfCategoryTitle"])
if ( chk )
indx = [theArray indexOfObject:aCategory];
}
Try this code much more simpler:-
int f = [yourArray indexOfObject:#"yourString"];
I have an NSMutableArray which only lasts during the session.
Currently I create it like this
NSMutableArray *temp = [[NSMutableArray alloc] initWithCapacity:10];
[self setScoreArray:temp];
[temp release];
Problem is when I go to check each index I'm getting an array outofbounds error
NSNumber *previousScore = [[self scoreArray] objectAtIndex:[self quizNum]];
if ( previousScore != nil )
{
[self clearQuizBtns];
NSInteger previousScoreValue = [previousScore integerValue];
[self selectButtonAtTag:previousScoreValue];
}else {
[self clearQuizBtns];
}
I've read in other posts that initWithCapacity doesn't actually create the array. So what can I populate the array with initially?
Thanks in advance.
Two ways:
first: to initiate array with default values of NSNull class
NSMutableArray *temp = [[NSMutableArray alloc] initWithCapacity:10];
for (int i = 0 ; i < 10 ; i++)
{
[temp insertObject:[NSNull null] atIndex:i];
}
[self setScoreArray:temp];
[temp release];
and then to check: if object is kind of NSNull class means it was a never set before
id previousScore = [[self scoreArray] objectAtIndex:[self quizNum]];
if (![previousScore isKindOfClass:[NSNull class]])
{
[self clearQuizBtns];
NSInteger previousScoreValue = [(NSNumber *)previousScore integerValue];
[self selectButtonAtTag:previousScoreValue];
}else {
[self clearQuizBtns];
}
second: store scores in NSMutableDictionary and use NSNumber's as keys
// scoreDictionary property of NSMutableDictionary class must be declared in self
NSNumber *previousScore = [self.scoreDictionary objectForKey:[NSNumber numberWithInt:[self quizNum]]];
if (previousScore != nil)
{
[self clearQuizBtns];
NSInteger previousScoreValue = [previousScore integerValue];
[self selectButtonAtTag:previousScoreValue];
}else {
[self clearQuizBtns];
}
NSArray does not support "holes". The capacity is just a hint to the initializer.
You could either fill the array with placeholder objects or, more typically, change your algorithm to either fully prepopulate the array or to lazy load it linearly.
Your problem seems to be that you're never actually setting any score in the score array.. are you? NSArrays have an actual count of items in them, and accessing an index beyond that count will blow up, as you've seen. If there will only ever be a fixed (small) number of scores, like 10, then you could set them all initially to something default like:
for (int i = 0; i < 10; i++) {
[temp addObject:[NSNumber numberWithInt:0]];
}
P.S. -initWithCapacity does "create the array", it just doesn't create any objects in the array. The capacity is a hint only.
Using the arrayWithObject: or arrayWithObjects: methods can provide an array with pre-populated values.
One cool thing about NSMutableArrays is that you can just do an "init" and the array will handle adding and removing objects on the fly. Remember that you generally addObject: or removeObjectAtIndex: when dealing with mutable arrays.