I have an array, that consist of following strings:
[NSString stringByAppendingFormat:#"<p style=\"padding-left:20px;margin-bottom:-10px;\"><i>%#%#%#%#</i></p>",
wrappingBy, pack1, pack2, strFirmName];
For example, it have 200 different strings. First parameter - wrappingBy, may have several different names. For example - box, tube, bag, etc.
What i want is, to enumerate through that array, and create different arrays depending on that name. So, if my array consist of 50 strings start from box, 50 strings start from tube, and 100 strings start from bag i want 3 different arrays.
Is there any easy way to achieve that?
Try this:
Let's say you have the array of strings:
NSArray *arr=#[#"box3523sfgsg",#"boxsdfsdf3",#"bag!#$#",#"!##4bag",#"tube##$FR",#"tubeASAD"];
In your case, the above array is filled with following string
[NSString stringByAppendingFormat:#"<p style=\"padding-left:20px;margin-bottom:-10px;\"><i>%#%#%#%#</i></p>",
wrappingBy, pack1, pack2, strFirmName];
Now add the wrappingBy param to the array everytime you add the above string to the array, and make sure you don;t add duplicates to the array. YOu can check the duplicates before adding them to the array.
and in your case, you would do
NSMutableArray *arrayNAme=[[NSMutableArray alloc]init];
//make arrayName mutable
if (![arrayNAme containsObject: wrappingBy]) {
[arrayNAme addObject: wrappingBy];
}
you will get arrayNAMe contain following:
arrayNAme=#[#"box",#"bag",#"tube"];
Now search the main array string if it contains the wrapingBy names or not, if YES, add them to an array and add that array to the dicitonary:
NSMutableDictionary *myDictionary=[[NSMutableDictionary alloc]init];
for( NSString *nameString in arrayNAme) {
NSMutableArray *strnArray=[[NSMutableArray alloc]init];
for (NSString *str in arr)
{
if([str containsString:nameString])
{
[strnArray addObject:str];
[myDictionary setValue:strnArray forKey:nameString];
}
}
}
At the end you have the dictionary:
{
bag = (
"bag!#$#",
"!##4bag"
);
box = (
box3523sfgsg,
boxsdfsdf3
);
tube = (
"tube##$FR",
tubeASAD
);
}
Now you can get each key value and store them in a separate array.
Related
Sorry guys, this problem I am running into is pretty trivial. I just can't wrap my head around it so hope someone can help me. Your help is really appreciated. I am getting JSON data through NSURLConnectDelegate with a web API. I get something like this back:
(
{
id = 340
name = Vicent },
{
id = 339
name = Johny },
{
id = 338
name = Eric }
)
and I save it in a NSMutableArray as a global variable. Now, I have a NSSet of "ids". For example:
{
340, 339
}
In the numberOfRowsInSection, I return the set's count. I am trying to load only the ids in the NSSet from the array with the data saved from the webAPI, so I do something like this in cellForRowIndexPath:
for (NSNumber *num in [set allObjects]) {
NSString *newString = [[savedArray objectAtIndex:indexPath.row]
NSString *new = [num stringValue];
if ([new isEqual:newString]) {
}}
How can I just populate the ids I want?
The JSON makes it look like you have an array of dictionaries, which is a reasonable data structure to use as the data source for a table view.
It sounds like you're trying to filter your array to only include the items that are in your set. Is that right?
If so, you could write code that would create a new array containing the subset of your array elements who's ID is also in your set. There are at least a half-dozen ways to do that. One fairly simple approach would be to use the NSArray method indexesOfObjectsPassingTest. You'd pass that method a block of code that would check each array element to see if it's id object was in your set.
That would give you an NSIndexSet with the indexes of the items in your array who's ID are in your set. Then you could use the NSArray method objectsAtIndexes to get an array of only the objects that are also in the set. Something like this (Assuming that your array of dictionaries is called savedArray and your set is called allObjects:
//get the indexes of items in the array savedArray who's id appears in the set allObjects
NSIndexSet *indexes = [savedArray indexesOfObjectsPassingTest:
^(NSDictionary *obj,
NSUInteger idx,
BOOL *stop)
{
return [allObjects member: obj[#"id"]] != nil;
}
];
//Now build an (immutable) array of just the objects who's ID are in the set
NSArray *subArray = [savedArray objectsAtIndexes: indexes];
The array subArray created above is immutable. If you need a mutable array you would need to make a mutable copy, which is a one-line change.
Disclaimer: I still struggle a little with block syntax, so the above might not be exactly correct, but it gives you the general idea.
I'm trying to access every name in the beers array for a search algorithm. I have the array set up as a dictionary,but it doesn't behave quite like a dictionary. Here is what the data looks like:
Just so you can see how I've been accessing the array, here is how I populated my uitableview.So, basically I know how to access individual objects in the arrray but I can't access the whole array. :
cell.detailTextLabel.text=[self.beers[indexPath.row] name]
Then again I might be totally off base. I'm still learning objective c and ios here so sorry if my inexperience shows through in my post. any tips help. Thanks guys!
I'm assuming that you want a new array that contains just the names of each Beer object and not the object itself. You can use an array "mapping" function like in this category.
typedef id(^MapBlock)(id input);
#implementation NSArray (Additions)
- (NSArray *)arrayByMappingWithBlock:(MapBlock)block {
NSMutableArray *array = [[NSMutableArray alloc] initWithCapacity:self.count];
for (id obj in self) {
[array addObject:block(obj)];
}
return array;
}
#end
You would then use it like so...
NSArray *beerNames = [self.beers arrayByMappingWithBlock:^id(Beer *beer) {
return beer.name;
}];
Not really sure if that is what you want to achieve, but the following line will produce an array containing all beer names:
[self.beers valueForKeyPath:#"name"];
You can access all of the names in the array by iterating through the array with a loop
for ( Beer *beer in self.beers )
NSLog( #"%#", beer.name );
This is another very specific problem I am trying to solve.
I am pulling a list a twitter user accounts logged into the users settings application. This returns an array with the usernames in the correct order.
I then pass this array to this twitter API:
https://api.twitter.com/1.1/users/lookup.json
The returned array contain all the additional data I need for each user account logged in. The first array contains NSStrings (usernames), the returned array has been parsed to contain dictionaries that have a key and value for the username, name, and profile pic.
Problem now is that the order is completely different than the first array I passed.. This is expected behavior from Twitter, but it needs to be in the exact same order (I will be referencing the original index of the AccountStore which will match the first array, but not the new array of dictionaries).
How can I tell the new array to match the contained dictionaries to be the same order as the first array based on the username key?
I know this sounds confusing, so let me at least post the data to help.
Here is the first array output:
(
kbegeman,
indeedyes,
soiownabusiness,
iphonedev4me
)
Here is what the second array outputs:
(
{
image = "https://si0.twimg.com/profile_images/3518542448/3d2862eee546894a6b0600713a8de862_normal.jpeg";
name = "Kyle Begeman";
"screen_name" = kbegeman;
},
{
image = "https://si0.twimg.com/profile_images/481537542/image_normal.jpg";
name = "Jane Doe";
"screen_name" = iPhoneDev4Me;
},
{
image = "https://twimg0-a.akamaihd.net/profile_images/378800000139973355/787498ff5a80a5f45e234b79005f56b5_normal.jpeg";
name = "John Doe";
"screen_name" = indeedyes;
},
{
image = "https://si0.twimg.com/sticky/default_profile_images/default_profile_5_normal.png";
name = "Brad Pitt";
"screen_name" = soiownabusiness;
}
)
Due to the way Twitter returns the data, it is never the EXACT same order, so I have to check this every time I call these methods.
Any help would be great, would save my night. Thanks in advance!
You want the array of dictionaries be sorted by comparing screen_name value with your first array. Right? Also, the screen name may have different case than your username. Right?
I would use mapping dictionary:
Create dictionary from screen name to user dictionary:
NSArray *screenNames = [arrayOfUserDicts valueForKeyPath:#"screen_name.lowercaseString"];
NSDictionary *userDictsByScreenName = [NSDictionary dictionaryWithObjects:arrayOfUserDicts forKeys:screenNames];
Build final array by finding user dictionary for usernames in your array:
NSMutableArray *sortedUserDicts = [NSMutableArray arrayWithCapacity:arrayOfUsernames.count];
for (NSString *username in arrayOfUsernames) {
NSDictionary *userDict = [userDictsByScreenName objectForKey:username.lowercaseString];
[sortedUserDicts addObject:userDict];
}
First generate a mapping that maps the "screen_name" to the corresponding dictionary
in the second array:
NSDictionary *map = [NSDictionary dictionaryWithObjects:secondArray
forKeys:[secondArray valueForKey:#"screen_name"]];
Then you can create the sorted array with a single loop:
NSMutableArray *sorted = [NSMutableArray array];
for (NSString *name in firstArray) {
[sorted addObject:map[name]];
}
That sort order isn't something that could be easily replicated (i.e. it's not alpha, etc). Instead, you should just use that original NSArray as a guide to match data from the NSDictionary from Twitter. For example:
[twitterDictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
NSInteger index = [yourLocalArray indexOfObject:obj];
if (index != NSNotFound) {
// You have a match, do something.
}
}];
lets name your arrays as firstArray and secondArray.
NSArray *sortedArray = [secondArray sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
return [#([firstArray indexOfObject:[obj1 objectForKey:#"name"]]) compare:#([firstArray indexOfObject:[obj2 objectForKey:#"name"]])];
}];
I need to append strings to an array kept inside of a dictionary each time a word matches a pattern of another word. The second line below (setObject) overwrites instead of appending.
The end result should be arrays in a dictionary where the the key(pattern) identifies many strings that fit that pattern.
NSMutableDictionary *eqClasses = [[NSMutableDictionary alloc] init];
[eqClasses setObject:tempWordStr forKey:wordPattern];
Is there an easy way to append?
Try this:
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];
You indicate that the values in the dictionary should be arrays, but it looks to me like eqClasses contains NSStrings (tempWordStr). Don't you need to create an NSArray to hold the NSStrings associated with a keyword and then make the array the value in the dictionary that corresponds to the keyword? If the dictionary already contains the key, you need to retrieve the array associated with the key, add the new string to the array, and then call setObject using the array with the key.
I need to scroll through several thousands of words to categorize them... to determine which words have the same pattern. (this part works)
For example, a four letter word that has two m's in 2nd & 4th position represent a pattern ("-m-m"). Once I have gone through all the words, I will know how many words there are for any given pattern. I am scrolling through now, but the problem I have is 'remembering' how many words I have in any given pattern.
I was thinking of using NSMutableDictionary and have the key be the pattern ('-m-m-') and the object represent the count of that pattern. This means every time I come across a pattern, I look up that pattern in the dictionary, get the key, increment the key, and put it back in the dictionary.
I need help with both the decision and syntax for performing this task.
Thank You
The answer to your question was this part of your (given) question "I will know how many words there are for any given pattern.". I would use an array of dictionary. You use the dictionary to store key value pair: a known pattern and the count. And you use the array to store those KVP records. So the next time you detect a pattern, search for the array for that record (dictionary), if found, increment the count. If not, create new record and set the count to 1.
Added sample code:
#define kPattern #"Pattern"
#define kPatternCount #"PatternCount"
-(NSMutableDictionary *)createANewDictionaryRecord:(NSString *) newPattern
{
int count = 1;
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:
newPattern, kPattern,
[NSString stringWithFormat:#"%i",count], kPatternCount,
nil];
return myDictionary;
}
-(void)addANewPatternToArray:(NSMutableDictionary *)newDictionary
{
// NSMutableArray *myArrayOfDictionary = [[NSMutableArray alloc]init]; // you need to define it somewhere else and use property etc.
[self.myArrayOfDictionary addObject:newDictionary]; //or [self.myArrayOfDictionary addObject:newDictionary]; if you follow the recommendation above.
}
-(BOOL)existingPatternLookup:(NSString *)pattern
{
for (NSMutableDictionary *obj in self.myArrayOfDictionary)
{
if ([[obj objectForKey:kPattern] isEqual:pattern])
{
int count = [[obj objectForKey:kPatternCount] intValue] + 1;
[obj setValue:[NSString stringWithFormat:#"%i",count] forKey:kPatternCount];
return YES;
}
}
[self.myArrayOfDictionary addObject:[self createANewDictionaryRecord:pattern]];
return NO;
}
-(void)testData
{
NSMutableDictionary *newDict = [self createANewDictionaryRecord:#"mmm"];
[self addANewPatternToArray:newDict];
}
-(void) printArray
{
for (NSMutableDictionary * obj in self.myArrayOfDictionary)
{
NSLog(#"mydictionary: %#", obj);
}
}
- (IBAction)buttonPressed:(id)sender
{
if ([self existingPatternLookup:#"abc"])
{
[self printArray];
} else
{
[self printArray];
}
}
Not being an objective C expert but solving this problem in java before, I would say a dictionary(I used a map when doing it in java) is the best way. Check if the key(pattern) already exist if so increment that count else put a new one in the dictionary.
EDIT
If you want to not just get the count of a pattern, but in fact tell which words fall under that pattern, I would use a dictionary of strings to mutable arrays. In the arrays you store the words and the key to the array is the pattern(as a string), similar code as above but instead of just incrementing the count, you have to add the new word to the array.
The only difference in NSDictionary and NSMutableDictionary is that one can have objects added to it. I think your implementation is good, but English is a complex language. It would be more efficient to parse out the string with regex than to set a key for it.
Why don't you use NSCountedSet instead:
NSCountedSet Class Reference
..which is available in iOS 2.0 and later?
Each distinct object inserted into an NSCountedSet object has a counter associated with it. NSCountedSetkeeps track of the number of times objects are inserted [...] Thus, there is only one instance of an object in an NSSet object even if the object has been added to the set multiple times. The count method defined by the superclass NSSet has special significance; it returns the number of distinct objects, not the total number of times objects are represented in the set.
Then use:
- (NSUInteger)countForObject:(id)anObject
Use a dictionary of NSMutableArrays, and check for the existence of each search key as you recommended. If the key doesn't exist, add an NSMutableSet or NSMutableArray (depending on your needs) for the searched key type "-m-m" for example, and then add to the set or array for that key.