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];
}
}
Related
I have to 2 NSMutableArrays containing NSMutableDictionarys. I need to verify the dictionaries in one of the arrays exists in the other array. How can I do this?
I'm not sure if this is the best approach but it is an easy one. I created a method to verify if a NSDictionary is present inside a NSArray. Inside this function, I convert the NSDictionarys to NSStrings and compare them.
- (BOOL)verifyIfDictionary:(NSDictionary *)dict existsInsideArray:(NSArray *)array
{
BOOL result = NO;
NSString *dictStr = [NSString stringWithFormat:#"%#",dict]; // convert dictionary to string
for (NSDictionary *d in arrayOfDictionaries)
{
NSString *dStr = [NSString stringWithFormat:#"%#",dict]; // same conversion as above conversion
// now, I just have to compare the resulting strings
if ([dictStr isEqualToString:dStr])
result = YES;
}
return result;
}
Now you just have to iterate through one of your NSArrays and use this method, like this:
NSArray *arrayOfDictionaries1;
NSArray *arrayOfDictionaries2;
// initialize them, fill with data, do your processing.. etc, etc...
// then, when you want to verify:
for (NSDictionary *dict in arrayOfDictionaries1)
{
if ([self verifyIfDictionary:dict existsInsideArray:arrayOfDictionaries2])
{
NSLog(#"exists!");
}
}
To check if array1 contains all of the items in array2:
NSMutableArray *mutableArrayToCheck = [array2 mutableCopy];
[mutableArrayToCheck removeObjectsInArray:array1];
if (array2.count > 0 && mutableArrayToCheck.count == 0) {
// array2 contains all the items in array1
}
Ignore the type of the contents of the arrays for a second, just think of numbers. We have 2 arrays:
array1 = [ 1, 2, 3 ]
array2 = [ 1, 3 ]
If we remove the items in array1 from array2, and the result is an empty array, then we know that all of the items in array2 were also in array1.
removeObjectsInArray: does this for us by searching through the array and comparing each item. We just need to check the result.
This works no matter what the contents of the array are, so long as they implement hash and isEqual:.
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;
}
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 am trying to detect if an array isn't empty in order to be able to do a certain call.
I tried using if (![array ==nil]) however that doesn't compile.
I'm sure there is a really easy explanation to this.
Update
If array is empty I want to do this:
array = [[NSMutableArray alloc]init];
If it has an object I want to do this:
array = [[userDefaults arrayForKey:#"MyFavorites"] mutableCopy];
If you declared it but did not assign anything to it at all:
NSMutableArray *array;
Then the array will be nil, meaning it isn't there at all so you can't say if it's empty or not, so you can't check anything.
If you did assign something to it, and you want to find out if the existing array is empty or not, that would depend on how you created it first.
If the array was assigned from some convenience method, it's autoreleased, so just do this:
if ([array count] == 0) {
array = [[NSMutableArray alloc] init];
} else {
array = [[userDefaults arrayForKey:#"MyFavorites"] mutableCopy];
}
If the array was assigned from an init or copy method, or it was retained previously, store the count in a temporary variable, release the array and use the temporary variable to decide what to do:
NSInteger count = [array count];
[array release];
if (count == 0) {
array = [[NSMutableArray alloc] init];
} else {
array = [[userDefaults arrayForKey:#"MyFavorites"] mutableCopy];
}
In your case I'd always use without differentation
array = [[userDefaults arrayForKey:#"MyFavorites"] mutableCopy];
and set the default value in the user defaults to an empty array right away at program start before accessing the defaults (from Apple's example):
+ (void)initialize{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *appDefaults = [NSDictionary
dictionaryWithObject:[NSArray array] forKey:#"MyFavorites"];
[defaults registerDefaults:appDefaults];
}
See Apple's doc on this.
Supposing you are talking about NSArray, if myArray has not been properly alloced+initialized (what you are trying to check) its reference will be nil, so you can do:
if(myArray) //or even if(myArray != nil) since myArray will be a pointer
{
//properly inizialized
}
else
{
//not properly inited
}
If it's been inited on the other hand, you can test its emptiness by checking the count property which returns the number of elements it contains
if([myArray > 0])
//there is at least one element
}
else
{
//no elements
}
you can use count function of NSArray. it will work on NSMutableArray too....
syntext will be,
int ct=[array count];
ct will have number of items in array.
if it us empty it will be Zero