Is there is a better way to convert NSArray of NSString into NSArray of NSNumber than the following code:
-(NSArray*) convertStringArrayToNumberArray:(NSArray *)strings {
NSMutableArray *numbers = [[NSMutableArray alloc] initWithCapacity:strings.count];
for (NSString *string in strings) {
[numbers addObject:[NSNumber numberWithInteger:[string integerValue]]];
}
return numbers;
}
-(NSArray *)convertStringArrayToNumberArray:(NSArray *)strings {
return [strings valueForKeyPath:#"self.integerValue"];
}
I test
NSArray * array = #[#"1",#"2",#"3"];
NSArray *num = [self convertStringArrayToNumberArray:array];
And result
Related
I want to use multiple sections feature UITableView. I have a single NSMutableArray which consists of data in dictionary format. In that dictionary there is a key which has values as '0' and '1'.
I want to create two separate NSMutableArray out of that so that I can assign them accordingly in different sections.
For example :
if (indexPath.section==0) {
NSDictionary *Data = [roomList1 objectAtIndex:indexPath.row];
} else {
NSDictionary *Data = [roomList2 objectAtIndex:indexPath.row];
}
Assuming the value in your dictionary is always set you could do something like:
NSMutableArray *firstArray = [NSMutableArray new];
NSMutableArray *secondArray = [NSMutableArray new];
for (NSDictionary *dictionary in yourArray) {
if ([dictionary objectForKey:#"yourValue"] isEqualToString: #"0") {
[firstArray addObject:dictionary];
} else if ([dictionary objectForKey:#"yourValue"]isEqualToString: #"1") {
[secondArray addObject:dictionary];
}
}
You can use this
- (NSDictionary *)groupObjectsInArray:(NSArray *)array byKey:(id <NSCopying> (^)(id item))keyForItemBlock
{
NSMutableDictionary *groupedItems = [NSMutableDictionary new];
for (id item in array) {
id <NSCopying> key = keyForItemBlock(item);
NSParameterAssert(key);
NSMutableArray *arrayForKey = groupedItems[key];
if (arrayForKey == nil) {
arrayForKey = [NSMutableArray new];
groupedItems[key] = arrayForKey;
}
[arrayForKey addObject:item];
}
return groupedItems;
}
Ref: Split NSArray into sub-arrays based on NSDictionary key values
Use like this
NSMutableArray * roomList1 = [[NSMutableArray alloc] init];
NSMutableArray * roomList2 = [[NSMutableArray alloc] init];
for(int i = 0;i< YourWholeArray.count;i++)
{
if([[[YourWholeArray objectAtIndex:i] valueForKey:#"YourKeyValueFor0or1"] isEqualToString "0"])
{
[roomList1 addObject:[YourWholeArray objectAtIndex:i]];
}
else if([[YourWholeArray objectAtIndex:i] valueForKey:#"YourKeyValueFor0or1"] isEqualToString "1"])
{
[roomList2 addObject:[YourWholeArray objectAtIndex:i]];
}
}
NSMutableArray *roomList1 = [[NSMutableArray alloc] init];
NSMutableArray *roomList2 = [[NSMutableArray alloc] init];
for (NSString *key in [myDictionary allKeys]) {
if (myDictionary[key] isEqualToString: #"0") {
[roomList1 addObject: myDictionary[key]];
} else {
[roomList2 addObject: myDictionary[key]];
}
}
try this way :-
NSMutableArray *getdata=[[NSMutableArray alloc]init];
getdata=[results objectForKey:#"0"];
NSMutableArray *getdata2=[[NSMutableArray alloc]init];
getdata2=[results objectForKey:#"1"];
use this two array and populate the section with now of rows at indexpathrow
define number of section 2
if (section==0){
getdata
}
else{
getdata2
}
- (void)loadData: (NSMutableArray *)myMutableArray {
self.myMutableDict = [[NSMutableDictionary alloc] init];
for (NSString *str in myMutableArray) {
NSString *key = [str substringToIndex:1];
NSLog(#"Key: %#", key);
NSLog(#"str: %#", str);
if ([self.myMutableDict objectForKey:key]) {
NSMutableArray *list = (NSMutableArray *)[self.myMutableDict objectForKey:key];
[list addObject:str];
[self.myMutableDict setObject:list forKey:key];
} else {
NSMutableArray *list = [[NSMutableArray alloc] initWithObjects:str, nil];
[self.myMutableDict setObject:list forKey:key];
}
}
[self.tblAlphabeticalOrder reloadData];
}
Your mutable array has only one very long string with lots of commas in it. You need to quote each item separately:
NSArray *array = [[NSArray alloc] initWithObjects:#"Shyam", #"Ram", #"Hari", #"Gita", .....
I have an NSArray with 10 NSStrings inside:
myArray (
#"21.32",
#"658.47",
#"87.32"...
)
What's the best way to convert all the strings to an NSDecimalNumber?
A very simple Category on NSArray will allow you to use map as seen in other languages
#interface NSArray (Functional)
-(NSArray *)map:(id (^) (id element))mapBlock;
#end
#implementation NSArray (Functional)
-(NSArray *)map:(id (^)(id))mapBlock
{
NSMutableArray *array = [#[] mutableCopy];
for (id element in self) {
[array addObject:mapBlock(element)];
}
return [array copy];
}
#end
Now you can use -map: in your case like
NSArray *array = #[#"21.32",
#"658.47",
#"87.32"];
array = [array map:^id(NSString *element) {
return [NSDecimalNumber decimalNumberWithString:element];
}];
A NSMutableArray in-place variant could be
#interface NSMutableArray (Functional)
-(void)map:(id (^) (id element))mapBlock;
#end
#implementation NSMutableArray (Functional)
-(void)map:(id (^)(id))mapBlock
{
[self enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
self[idx] = mapBlock(obj);
}];
}
#end
NSMutableArray *array = [#[#"21.32",
#"658.47",
#"87.32"] mutableCopy];
[array map:^id(NSString *element) {
return [NSDecimalNumber decimalNumberWithString:element];
}];
It would be quite simple with a for loop:
myArray (
#"21.32",
#"658.47",
#"87.32"...
)
NSMutableArray *numberArray = [NSMutableArray arrayWithCapacity: myArray.count];
for (aString in myArray)
{
NSDecimalNumber *aNumber = [NSDecimalNumber decimalNumberWithString: aString];
[numberArray addObject: aNumber];
}
This question already has answers here:
Avoiding "NSArray was mutated while being enumerated"
(11 answers)
Closed 7 years ago.
I want to remove object from array when the name is same. How to do this? Thanks in advance. Here is my code
NSString *name1;
NSString *name2;
NSArray *copyArray = [uniqueArraySort copy];
for (NSMutableDictionary *dict1 in copyArray) {
for (NSDictionary *dict2 in uniqueArraySort) {
name1 = [dict1 valueForKey:#"name"];
name2 = [dict2 valueForKey:#"name"];
if ([name1 isEqualToString:name2]) {
NSLog(#"%#",uniqueArraySort);
[uniqueArraySort removeObject:dict2];
NSLog(#"%#",uniqueArraySort);
}
}
}
And when I compile I get this error
<__NSArrayM: 0x7fea39804f40> was mutated while being enumerated.'
Try something like this... I assume value for key "name" might be a string.
NSSet *set = [NSSet setWithArray:[uniqueArraySort valueForKey:#"name"]];
NSMutableArray *array = [NSMutableArray new];
for (NSString* value in set.allObjects) {
NSArray *filteredArray = [uniqueArraySort filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"name = %#", value]];
if(filteredArray.count > 0)
[array addObject:[filteredArray firstObject]];
}
return array;
UPDATE : On second thought, I found that code above is still too much. You can do it at O(n) using hashtable.
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] initWithCapacity:uniqueArraySort.count];
for(NSDictionary *item in uniqueArraySort)
{
NSString *name = [item objectForKey:#"name"];
if([dictionary objectForKey:name] == nil)
{
[dictionary setObject:item forKey:name];
}
}
return dictionary.allValues;
What you need to do is create a separate mutable array. Something like this:
NSMutableArray *itemsToDelete = [NSMutableArray array];
NSMutableArray *copyArray = [uniqueArraySort mutableCopy];
for (NSMutableDictionary *dict1 in copyArray) {
for (NSDictionary *dict2 in uniqueArraySort) {
name1 = [dict1 valueForKey:#"name"];
name2 = [dict2 valueForKey:#"name"];
if ([name1 isEqualToString:name2]) {
NSLog(#"%#",uniqueArraySort);
[itemsToDelete addObject:dict2];
NSLog(#"%#",uniqueArraySort);
}
}
}
[copyArray removeObjectsInArray:itemsToDelete];
Also, I'm not sure what you are doing with uniqueArraySort but you might need to make that an NSMutableArray if you plan on using it after.
I Had an exception in the line [array removeObjectsInArray:toRemove]; in the method below and can't understand what's wrong with it..
- (void) handleDearchForTerm:(NSString *)searchTerm
{
NSMutableArray *sectionsToRemove = [[NSMutableArray alloc] init];
[self resetSearch];
for (NSString *key in _keys)
{
NSMutableArray *array = [_names valueForKey:key];
NSMutableArray *toRemove = [[NSMutableArray alloc] init];
for (NSString *name in array)
{
if ([name rangeOfString:searchTerm options:NSCaseInsensitiveSearch].location == NSNotFound)
[toRemove addObject:name];
}
if ([array count] == [toRemove count])
[sectionsToRemove addObject:key];
[array removeObjectsInArray:toRemove];
}
[_keys removeObjectsInArray:sectionsToRemove];
[_table reloadData];
}
Probably array is just instance of NSArray， but not NSMutableArray, you shall check _names setObject:forKeys:
Change:
NSMutableArray *array = [_names valueForKey:key];
To:
NSMutableArray *array = [[NSMutableArray alloc] initWithArray:[_names valueForKey:key]];
Or:
NSMutableArray *array = [[_names valueForKey:key] mutableCopy];