I try to find object in my array and if success I need to replace object from my array to new object
for (id existingSig in allSignature)
if ([[existingSig objectForKey:#"SignatureName"] isEqualToString:[item objectForKey:#"name"]])
{
[allSignature removeObject:existingSig];
[allSignature addObject:[NSDictionary dictionaryWithObjectsAndKeys:#"1", #"SignatureIsRich", [item objectForKey:#"name"], #"SignatureName", generatedID, #"SignatureUniqueId", nil]];
}
I have error 'NSCFArray: 0x100551f10> was mutated while being enumerated'
As others have said, you cannot mutate a MutableArray while it is being Enumerated. You could handle it by having two arrays of what to remove and what to add after the loop.
NSMutableArray *remove = [NSMutableArray array];
NSMutableArray *add = [NSMutableArray array];
for (id existingSig in allSignature){
if ([[existingSig objectForKey:#"SignatureName"] isEqualToString:[item objectForKey:#"name"]])
{
// Add to the array of objects to be removed
[remove addObject:existingSig];
// Add to the array of objects to be added
[add addObject:[NSDictionary dictionaryWithObjectsAndKeys:#"1", #"SignatureIsRich", [item objectForKey:#"name"], #"SignatureName", generatedID, #"SignatureUniqueId", nil]];
}
}
[allSignature removeObjectsInArray:remove]; // Remove objects
[allSignature addObjectsFromArray:add]; // Add new objects
The easiest way is to make a copy and iterate over that, then modify the original.
I have a map array method I have in a NSArray Category for this very purpose
- (NSArray *) cw_mapArray:(id (^)(id obj))block
{
NSMutableArray * cwArray = [[NSMutableArray alloc] init];
[self cw_each:^(id obj, NSUInteger index, BOOL *stop) {
id rObj = block(obj);
if (rObj) {
[cwArray addObject:rObj];
}
}];
return cwArray;
}
this way I can get a new array and then just change the array with the new array. You can change cw_each to enumerateObjectsUsingBlock:. Basically this is simple, if you want to map the object to the new array you just return the object as is in the block, otherwise modify it and return that or if you don't want to map the object to the new array then return nil. Its not very much code and works wonderfully.
Related
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;
}
If I instantiate an NSArray passing it an NSMutableArray, does it become a NSArray or does it just appear to be one.
i.e. is the mutable array eventually released
- (NSArray *)getObjectivesWithPerspective:(Perspective *)perspective
{
NSMutableArray *result = [NSMutableArray array];
for (ObjectiveManagedObject *objective in self.objectives)
{
if (objective.perspective.objectID == perspective.objectID) {
[result addObject:objective];
}
}
return [NSArray arrayWithArray:result];
}
See this answer: https://stackoverflow.com/a/1392051/254422
Basically, it copies the objects into a new, autoreleased, immutable NSArray.
The NSMutableArray created using +array is autoreleased.
You can find some info about this here: what does -arrayWithArray actually DO?. But the array you get back should be immutable. NSArray will copy the references into an immutable array.
If in doubt do a test. Get an array back from the method, cast it as a NSMutableArray and try to add an object. You should get an error when you do this.
As NSMutableArray is a subclass of NSArray, you can return result directly without the need to create a new NSArray object:
- (NSArray *)getObjectivesWithPerspective:(Perspective *)perspective
{
NSMutableArray *result = [NSMutableArray array];
for (ObjectiveManagedObject *objective in self.objectives)
{
if (objective.perspective.objectID == perspective.objectID) {
[result addObject:objective];
}
}
return result;
}
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"];
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.
I want to know that how can I add NSMutableArray in to an NSMutableArray so that previous data should not lost, and new data will be added on next indexes.
If you don't understand it then you can ask again to me,
I will appraise the right answer.
my code is as below
-(void)setArray1:(NSMutableArray *)arrayValueFromNew
{
self.myArray=arrayValueFromNew;
myArray2 = [[NSMutableArray alloc] initWithArray:arrayValueFromNew];
for(int i=0;i<[myArray2 count];i++)
{
[myArray addObject:[myArray2 objectAtIndex:i]];
}
}
In your code, myArray and myArray2, both have same objects as you are assigning the arrayValueFromNew array to both. So it kind of doesn't make sense.
But to answer your question 'how to add one array to another?' do :
[mutableArray1
addObjectsFromArray:array2];
EDIT:
this is how your method should look
-(void)setArray1:(NSMutableArray *)arrayValueFromNew
{
if(!self.myArray)
{
self.myArray = arrayValueFromNew;
}
else
{
[self.myArray addObjectsFromArray:arrayValueFromNew];
}
}
Your 'myArray must be initialized. You can initialize it in viewDidLoad or init:
self.myArray = [[NSMutableArray alloc]
initWithCapacity:1];
NSMutableArray *array1 = [NSMutableArray array], *array2 = [NSMutableArray array];
// add some objects to the arrays
[array1 addObjectsFromArray:array2];
//array1 now contains all the objects originally in array1 and array2
This will work,
NSMutableArray *mutarr=[[NSMutableArray alloc]initWithArray: array1]
It looks like you just want a new copy of the old array. There is a handy function for that
NSMutableArray *newArray = [oldArray mutableCopy];
Remember that you've used copy in getting this array so you are responsible for managing the memory of newArray
EDIT
What is your code doing?
-(void)setArray1:(NSMutableArray *)arrayValueFromNew //1
{
self.myArray=arrayValueFromNew; //2
myArray2 = [[NSMutableArray alloc] initWithArray:arrayValueFromNew]; //3
for(int i=0;i<[myArray2 count];i++)
{
[myArray addObject:[myArray2 objectAtIndex:i]]; //4
}
}
This looks like a setter for a property array1
You are setting the property 'array' to arrayValueFromNew. Since I don't know whether this property has been declared with retain or copy I don't know whether array is a pointer to arrayValueFromNew or a pointer to a copy of arrayValueFromNew
You set myArray2 to be a new array that contains the objects of arrayValueFromNew
For each object in myArray2 (which are the objects from arrayValueFromNew. see point 3) you add this object to myArray. Assuming myArray is an NSMutableArray it started with the objects from arrayValueFromNew which you have now added again. It contains each item in arrayValueFromNew twice.