Sorting NSArray of Dictionary containing Date as String - ios

I want to sort the following array based on the Date parameter but the problem is from a server I am not getting a timestamp, I am getting the date as a string, can anyone please help.
NSArray *array = #[
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"17-05-2019",#"rtntype":#"CODE1",#"ret_prd":#"042019"},
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"19-04-2019",#"rtntype":#"CODE1",#"ret_prd":#"032019"},
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"19-04-2019",#"rtntype":#"CODE2",#"ret_prd":#"032019"}
];
I have tried applying the solution but it won't work as the Date we have is in NSString and not in NSDate or NSTimeInterval
[array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
if ([obj1 intValue] == [obj2 doubleValue])
return NSOrderedSame;
else if ([obj1 intValue] < [obj2 doubleValue])
return NSOrderedAscending;
else
return NSOrderedDescending;
}];

I am assuming you have a specific reason to keep data as it is instead of parsing into model class keep it handy.
In your scenario you could try the following code to sort the array:
NSArray *array = #[
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"19-04-2019",#"rtntype":#"CODE1",#"ret_prd":#"032019"},
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"17-05-2019",#"rtntype":#"CODE1",#"ret_prd":#"042019"},
#{#"valid":#"Y",#"mof":#"ON",#"dof":#"19-04-2019",#"rtntype":#"CODE2",#"ret_prd":#"032019"}
];
//NSDateFormatter to convert NSString to NSDate
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy"];
NSArray *sortedArray = [array sortedArrayUsingComparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
if ([obj1 isKindOfClass:[NSDictionary class]]
&& [obj2 isKindOfClass:[NSDictionary class]]) {
NSDictionary *dict1 = (NSDictionary *)obj1;
NSDictionary *dict2 = (NSDictionary *)obj2;
if ([dict1[#"dof"] isKindOfClass:[NSString class]]
&& [dict2[#"dof"] isKindOfClass:[NSString class]]) {
NSString *dof1 = (NSString *) dict1[#"dof"];
NSString *dof2 = (NSString *) dict2[#"dof"];
NSDate *date1 = [formatter dateFromString:dof1];
NSDate *date2 = [formatter dateFromString:dof2];
return [date1 compare:date2];//Update the return based on in which order you want the resulting array
}
}
return NSOrderedSame;
}];
NSLog(#"%#", sortedArray);
And the result is:
(
{
dof = "19-04-2019";
mof = ON;
"ret_prd" = 032019;
rtntype = CODE1;
valid = Y;
},
{
dof = "19-04-2019";
mof = ON;
"ret_prd" = 032019;
rtntype = CODE2;
valid = Y;
},
{
dof = "17-05-2019";
mof = ON;
"ret_prd" = 042019;
rtntype = CODE1;
valid = Y;
}
)

Related

Max value for each object in an Array of Dictionaries

I have an array of dictionaries that I am trying to get the Max score for each player in the array. Each player can have multiple entries I am trying to get an array of dictionaries of each players best score.
NSArray
[0] - NSDictionary
- [0] Score: (double)20.7
- [1] NameID: (int) 1
- [2] Date
[1] - NSDictionary
- [0] Score: (double)25
- [1] NameID: (int) 1
- [2] Date
[2] - NSDictionary
- [0] Score: (double)28
- [1] NameID: (int) 2
- [2] Date
[3] - NSDictionary`
- [0] Score: (double)26
- [1] NameID: (int) 3
- [2] Date
I have tried using NSPredicate predicateWithFormat but I am only able to get back the max for everything in the array not related to the name.
Expected Output:
NSArray
[1] - NSDictionary
- [0] Score: (double)25
- [1] NameID: (int) 1
- [2] Date
[2] - NSDictionary
- [0] Score: (double)28
- [1] NameID: (int) 2
- [2] Date
[3] - NSDictionary`
- [0] Score: (double)26
- [1] NameID: (int) 3
- [2] Date
Thanks for the help.
You can't use an NSPredicate for this, since you want to determine the maximum score for several different players. Under the covers, NSPredicate iterates the array anyway, so using your own loop isn't any less efficient. In the following code I have assumed that the scores and player names are wrapped in NSNumber
-(NSArray *)maxScoresForPlayers:(NSArray *)playerScores {
NSMutableDictionary *maxScores = [NSMutableDictionary new];
for (NSDictionary *player in playerScores) {
NSNumber *playerID = (NSNumber *)player[#"NameID"];
NSDictionary *playerMax = maxScores[playerID];
if (playerMax == nil) {
playerMax = player;
} else {
NSNumber *currentMax = (NSNumber *)[playerMax[#"Score"];
NSNumber *playerScore = (NSNumber *)player[#"Score"];
if ([playerScore doubleValue] > [currentMax doubleValue]) {
playerMax = player;
}
}
maxScores[playerID] = playerMax;
}
return([maxScores allValues];
}
You can do it manually like this:
NSMutableDictionary *maxScoresDict = [NSMutableDictionary dictionary];
for (NSDictionary *score in scoresArray) {
NSNumber *key = score[#"NameID"];
NSNumber *savedMax = maxScoresDict[key][#"Score"];
NSNumber *currentMax = maxScoresDict[key][#"Score"];
if (savedMax == nil || [currentMax doubleValue] > [savedMax doubleValue]) {
maxScoresDict[key] = score;
}
}
NSArray *maxScoresArray = [maxScoresDict allValues];
Try this:
NSArray *objects = #[#{#"Score": #(20.7),
#"NameID": #(1),
#"Date": [NSDate date]},
#{#"Score": #(25),
#"NameID": #(1),
#"Date": [NSDate date]},
#{#"Score": #(28),
#"NameID": #(2),
#"Date": [NSDate date]},
#{#"Score": #(26),
#"NameID": #(3),
#"Date": [NSDate date]}];
NSMutableArray *users = [NSMutableArray array];
for (NSInteger i=0; i<objects.count; i++) {
NSDictionary *dict = objects[i];
NSNumber *nameID = dict[#"NameID"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"self.NameID==%#", nameID];
NSInteger index = [users indexOfObjectPassingTest:^BOOL(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
BOOL found = [predicate evaluateWithObject:obj];
return found;
}];
if (index != NSNotFound) {
NSNumber *score1 = dict[#"Score"];
NSNumber *score2 = users[index][#"Score"];
if (score1.doubleValue > score2.doubleValue) {
[users replaceObjectAtIndex:index withObject:dict];
}
}
else {
[users addObject:dict];
}
}
NSLog(#"%#", users);
- (NSArray *)getBestScores:(NSArray *)players {
NSMutableDictionary *best = [[NSMutableDictionary alloc] init];
for (NSDictionary *p in players) {
NSDictionary *b = [best valueForKey:[p valueForKey:#"NameID"]];
if (!b || [[p valueForKey:#"Score"] doubleValue] > [[b valueForKey:#"Score"] doubleValue])
[best setValue:p forKey:[p valueForKey:#"NameID"]];
}
return [best allValues];
}
// Get Max Value of integer element from Array of Dictonaries.
// Example Array Starts
<paramArray>(
{
DicID = 1;
Name = "ABC";
ValuetoCalculateMax = 2800;
},
{
DicID = 2;
Name = "DEF";
ValuetoCalculateMax = 2801;
},
{
DicID = 3;
Name = "GHI";
ValuetoCalculateMax = 2805;
}
)
// Example Array Ends
// Implementation
int MaxintegerValue=0;
MaxintegerValue=[self getMaxValueFromArrayofDictonaries:paramArray];
// Implementation Ends
// Function Starts
-(int)getMaxValueFromArrayofDictonaries:(NSArray *)paramArray
{
int MaxValue=0;
NSMutableDictionary *dic=[[NSMutableDictionary alloc]init];
for ( int i=0; i<[paramArray count]; i++ )
{
dic=[paramArray objectAtIndex:i];
if ([[dic valueForKey:#"ValuetoCalculateMax"] intValue] > MaxValue)
{
MaxValue=[[dic valueForKey:#"ValuetoCalculateMax"] intValue];
}
else
{
MaxValue=MaxValue;
}
}
return MaxValue;
}
// Function Ends
What you need to do is find scores for each user, then find the max score out of it.
- (void)findMaxScoreForUser:(int)userId {
NSDictionary *dict0 = [NSDictionary dictionaryWithObjects:#[#27.0,#3] forKeys:#[#"Score",#"UserID"]];
NSDictionary *dict1 = [NSDictionary dictionaryWithObjects:#[#25.0,#2] forKeys:#[#"Score",#"UserID"]];
NSDictionary *dict2 = [NSDictionary dictionaryWithObjects:#[#23.0,#3] forKeys:#[#"Score",#"UserID"]];
NSArray *arr = [NSArray arrayWithObjects:dict0,dict1,dict2, nil];
NSMutableArray *scores = [NSMutableArray array];
for (NSDictionary *dict in arr) {
int userID = [[dict valueForKey:#"UserID"] intValue];
if (userId == userID) {
[scores addObject:[dict valueForKey:#"Score"]];
}
}
int max = [[scores valueForKeyPath:#"#max.intValue"] intValue];
}

EXC_BAD_ACCESS. Completion block

ANSWER
I heve a mistake when i call the fetchDailyForecast it should looks like
[self.fetchController fetchDailyForecast:self.currentLocation.coordinate completionBlock:^(DailyModel *newModel) {
_dailyCondition = newModel;
NSLog(#"newModel = %#", _dailyCondition);
}];
END
I try to use bloc's and wait but have a bad_access exaction. Firstly i call method from MangeDataController.m
[self.fetchController
fetchDailyForecast:self.currentLocation.coordinate
completionBlock:(void(^)(DailyModel *))_dailyCondition];
where the dailyCondition is instance of DailyModel.
Secondly here is fetchDailyForecast method realization in FetchController.m.
-(void)fetchDailyForecast:(CLLocationCoordinate2D)coordinate completionBlock:(void(^)(DailyModel *))completionBlock {
NSString *urlString = [NSString stringWithFormat:#"http://api.openweathermap.org/data/2.5/forecast/daily?lat=%f&lon=%f&units=imperial&cnt=7%#", coordinate.latitude, coordinate.longitude, _key];
urlString = [urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLFragmentAllowedCharacterSet]];
[self fetchJSONfromURL:urlString completionBlock:^(NSDictionary *weatherData) {
completionBlock([[DailyModel alloc] dataFromDictionaryDaily:weatherData]); --- (here the bad access);
}];
}
and thirdly in fatchDailyForecast i call fetchJSONfromURL here is realization:
-(void)fetchJSONfromURL:(NSString *)urlString completionBlock:(void (^)(NSDictionary *))completionBlock {
NSLog(#"url = %#", urlString);
[_manager GET:urlString parameters:nil progress:nil success:^(NSURLSessionTask *task, id responceObject) {
if (responceObject) {
completionBlock(responceObject);
} else {
NSLog(#"responce object error");
}
}
failure:^(NSURLSessionTask *operation, NSError *error){
NSLog(#"error %#", error);
}];
}
P.S. I think my mistake is that i try to pass day _dailyCondition but should pass something different. Thanks for any help!
**EDIT ------- DailyModel.m **
#import "DailyModel.h"
#implementation DailyModel
-(id)dataFromDictionaryDaily:(NSDictionary *)dic {
NSArray *arrayWithDictionarys = [dic objectForKey:#"list"];
NSDictionary *dictionaryWithWeekDays = [self indexKeyedDictionaryFromArray:arrayWithDictionarys];
// NSLog(#"dictionary with dayweeks = %#", dictionaryWithWeekDays);
_arrayWithTemp = [NSMutableArray new];
_arrayWithDate = [NSMutableArray new];
_arrayWithIcon = [NSMutableArray new];
for (int i = 0; i <= 6; i++) {
NSNumber* key = [NSNumber numberWithInt:i];
[self addValuesToArrayWithTemp:dictionaryWithWeekDays key:key index:i];
[self addValuesToArrayWithDate:dictionaryWithWeekDays key:key index:i];
[self addValueToArrayWithImage:dictionaryWithWeekDays key:key index:i];
}
return self;
}
- (NSDictionary *) indexKeyedDictionaryFromArray:(NSArray *)array
{
NSMutableDictionary *mutableDictionary = [[NSMutableDictionary alloc] init];
[array enumerateObjectsUsingBlock:
^(id obj, NSUInteger idx, BOOL *stop){
NSNumber *index = [NSNumber numberWithInteger:idx];
[mutableDictionary setObject:obj forKey:index];
}];
NSDictionary *result = [NSDictionary.alloc initWithDictionary:mutableDictionary];
return result;
}
-(void) addValuesToArrayWithTemp:(NSDictionary *)inputDic key:(NSNumber *)key index:(int)ind {
NSDictionary *currentDic = [inputDic objectForKey:key];
NSDictionary *temp = [currentDic objectForKey:#"temp"];
_tempLow = [temp objectForKey:#"min"];
_tempHigh = [temp objectForKey:#"max"];
_tempLow = [self convertToCelsius:_tempLow];
_tempHigh = [self convertToCelsius:_tempHigh];
NSString *tempString = [NSString stringWithFormat:#"%.02f / %.02f", _tempLow.floatValue , _tempHigh.floatValue];
[_arrayWithTemp insertObject:tempString atIndex:ind];
}
-(NSNumber *)convertToCelsius:(NSNumber *)far {
double f = (far.doubleValue - 32) / 1.8;
NSNumber *celsius = [NSNumber numberWithDouble:f];
return celsius;
}
-(void) addValuesToArrayWithDate:(NSDictionary *)inputDic key:(NSNumber *)key index:(int)ind {
NSDictionary *currenDic = [inputDic objectForKey:key];
NSNumber *tempNumber = [currenDic objectForKey:#"dt"];
double unixTimeStamp = tempNumber.doubleValue;
NSString* weekDay = [self convertToWeekDay:unixTimeStamp];
[_arrayWithDate insertObject:weekDay atIndex:ind];
}
-(NSString *)convertToWeekDay:(double) unixtime {
NSTimeInterval _interval = unixtime;
NSDate *date = [NSDate dateWithTimeIntervalSince1970:_interval];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setLocale:[NSLocale currentLocale]];
[formatter setDateFormat:#"EEEE"];
NSString *dateString = [formatter stringFromDate:date];
return dateString;
}
-(void) addValueToArrayWithImage:(NSDictionary *)inputDic key:(NSNumber *)key index:(int)ind {
NSDictionary *currenDic = [inputDic objectForKey:key];
NSArray *weatherArray = [currenDic objectForKey:#"weather"];
NSDictionary *weather = weatherArray[0];
_icon = [weather objectForKey:#"icon"];
_icon = [self currentImageString:_icon];
[_arrayWithIcon insertObject:_icon atIndex:ind];
}
-(NSString *)currentImageString:(NSString *)ico {
NSDictionary *dic = #{
#"01d" : #"weather-clear",
#"02d" : #"weather-few",
#"03d" : #"weather-few",
#"04d" : #"weather-broken",
#"09d" : #"weather-shower",
#"10d" : #"weather-rain",
#"11d" : #"weather-tstorm",
#"13d" : #"weather-snow",
#"50d" : #"weather-mist",
#"01n" : #"weather-moon",
#"02n" : #"weather-few-night",
#"03n" : #"weather-few-night",
#"04n" : #"weather-broken",
#"09n" : #"weather-shower",
#"10n" : #"weather-rain-night",
#"11n" : #"weather-tstorm",
#"13n" : #"weather-snow",
#"50n" : #"weather-mist",
};
ico = [dic objectForKey:ico];
return ico;
}
#end
EDIT 2
I add the condition into (void)fetchDailyForecast:(CLLocationCoordinate2D)coordinate completionBlock:(void(^)(DailyModel *))completionBlock and now app don't crash but it's still not work and nslog say #"nothing"
[self fetchJSONfromURL:urlString completionBlock:^(NSDictionary
*weatherData) { if (completionBlock) { completionBlock(model = [[DailyModel alloc] dataFromDictionaryDaily:weatherData]); } else {
NSLog(#"nothing"); } }];

iOS: Reorder NSString characters alphabetically [duplicate]

I'm trying to re-arrange words into alphabetical order. For example, tomato would become amoott, or stack would become ackst.
I've found some methods to do this in C with char arrays, but I'm having issues getting that to work within the confines of the NSString object.
Is there an easier way to do it within the NSString object itself?
You could store each of the string's characters into an NSArray of NSNumber objects and then sort that. Seems a bit expensive, so I would perhaps just use qsort() instead.
Here it's provided as an Objective-C category (untested):
NSString+SortExtension.h:
#import <Foundation/Foundation.h>
#interface NSString (SortExtension)
- (NSString *)sorted;
#end
NSString+SortExtension.m:
#import "NSString+SortExtension.h"
#implementation NSString (SortExtension)
- (NSString *)sorted
{
// init
NSUInteger length = [self length];
unichar *chars = (unichar *)malloc(sizeof(unichar) * length);
// extract
[self getCharacters:chars range:NSMakeRange(0, length)];
// sort (for western alphabets only)
qsort_b(chars, length, sizeof(unichar), ^(const void *l, const void *r) {
unichar left = *(unichar *)l;
unichar right = *(unichar *)r;
return (int)(left - right);
});
// recreate
NSString *sorted = [NSString stringWithCharacters:chars length:length];
// clean-up
free(chars);
return sorted;
}
#end
I think separate the string to an array of string(each string in the array contains only one char from the original string). Then sort the array will be OK. This is not efficient but is enough when the string is not very long. I've tested the code.
NSString *str = #"stack";
NSMutableArray *charArray = [NSMutableArray arrayWithCapacity:str.length];
for (int i=0; i<str.length; ++i) {
NSString *charStr = [str substringWithRange:NSMakeRange(i, 1)];
[charArray addObject:charStr];
}
NSString *sortedStr = [[charArray sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)] componentsJoinedByString:#""];
// --------- Function To Make an Array from String
NSArray *makeArrayFromString(NSString *my_string) {
NSMutableArray *array = [[NSMutableArray alloc] init];
for (int i = 0; i < my_string.length; i ++) {
[array addObject:[NSString stringWithFormat:#"%c", [my_string characterAtIndex:i]]];
}
return array;
}
// --------- Function To Sort Array
NSArray *sortArrayAlphabetically(NSArray *my_array) {
my_array= [my_array sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
return my_array;
}
// --------- Function Combine Array To Single String
NSString *combineArrayIntoString(NSArray *my_array) {
NSString * combinedString = [[my_array valueForKey:#"description"] componentsJoinedByString:#""];
return combinedString;
}
// Now you can call the functions as in below where string_to_arrange is your string
NSArray *blowUpArray;
blowUpArray = makeArrayFromString(string_to_arrange);
blowUpArray = sortArrayAlphabetically(blowUpArray);
NSString *arrayToString= combineArrayIntoString(blowUpArray);
NSLog(#"arranged string = %#",arrayToString);
Just another example using NSMutableString and sortUsingComparator:
NSMutableString *mutableString = [[NSMutableString alloc] initWithString:#"tomat"];
[mutableString appendString:#"o"];
NSLog(#"Orignal string: %#", mutableString);
NSMutableArray *charArray = [NSMutableArray array];
for (int i = 0; i < mutableString.length; ++i) {
[charArray addObject:[NSNumber numberWithChar:[mutableString characterAtIndex:i]]];
}
[charArray sortUsingComparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
if ([obj1 charValue] < [obj2 charValue]) return NSOrderedAscending;
return NSOrderedDescending;
}];
[mutableString setString:#""];
for (int i = 0; i < charArray.count; ++i) {
[mutableString appendFormat:#"%c", [charArray[i] charValue]];
}
NSLog(#"Sorted string: %#", mutableString);
Output:
Orignal string: tomato
Sorted string: amoott

UITableView scroll to section that is closest to todays date

I have a tableview with a calendar it's appointments in it. Each day is a separate section.
You can see what I mean over here
Now I want that the tableview scrolls to the section of today or if there is no section for today to the closest one.
I know that I should use the following piece of code:
[tableView scrollToRowAtIndexPath:scrollIndexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
Now I have an NSMutableDictionary that contains my sorted Appointments/day. You can see the function below:
-(NSDictionary *)sortKalendar:(NSMutableArray *)appointments{
NSMutableDictionary *buffer = [[NSMutableDictionary alloc] init];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy"];
for (int i = 0; i < appointments.count; i++) {
Appointment *object = [appointments objectAtIndex:i];
NSString *date = [formatter stringFromDate:object.app_start];
if(!(date == NULL) ){
NSLog(#"date is %#",date);
if ([buffer objectForKey:date]) {
[(NSMutableArray *)[buffer objectForKey:date] addObject:object];
} else {
NSMutableArray *mutableArray = [[NSMutableArray alloc] initWithObjects:object, nil];
[buffer setObject:mutableArray forKey:date];
}
}
}
NSDictionary *result = [NSDictionary dictionaryWithDictionary:buffer];
return result;
}
My question is now, how can I find the correct NSIndexpath ?
Thanks in advance !
EDIT
At the moment I'm using the following. But something is still not right.
NSArray *keys = [dictAppointments allKeys];
NSLog(#"KEYS ARE %#",keys) ;
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy"];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^(id obj1, id obj2) {
NSDate *date1 = [formatter dateFromString:obj1];
NSDate *date2 = [formatter dateFromString:obj2];
NSNumber *interval1 = [NSNumber numberWithDouble:[date1 timeIntervalSinceNow]];
NSNumber *interval2 = [NSNumber numberWithDouble:[date2 timeIntervalSinceNow]];
return (NSComparisonResult)[interval1 compare:interval2];
}];
NSLog(#"Sorted Array %#",sortedArray);
NSString *closestDateString = [sortedArray objectAtIndex:0];
NSLog(#"Closest date string is %#",closestDateString);
int section = [keys indexOfObject:closestDateString];
NSIndexPath *scrollIndexPath = [NSIndexPath indexPathForRow:0 inSection:section];
[tableView scrollToRowAtIndexPath:scrollIndexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
This gives me the following logs:
2014-01-07 13:28:42.420 Adsolut[9579:60b] KEYS ARE (
"03-12-2013",
"20-12-2013",
"17-12-2013",
"05-01-2014",
"21-12-2013",
"31-12-2013",
"04-01-2014",
"06-01-2014",
"16-01-2014",
"29-12-2013",
"03-01-2014",
"11-01-2014",
"18-12-2013",
"31-01-2014"
)
2014-01-07 13:28:42.437 Adsolut[9579:60b] Sorted Array (
"03-12-2013",
"17-12-2013",
"18-12-2013",
"20-12-2013",
"21-12-2013",
"29-12-2013",
"31-12-2013",
"03-01-2014",
"04-01-2014",
"05-01-2014",
"06-01-2014",
"11-01-2014",
"16-01-2014",
"31-01-2014"
)
You can sort the array using time interval between appointment date and current date,
NSArray *keys = [yourDictionary allKeys];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy"];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^(id obj1, id obj2) {
NSDate *date1 = [formatter dateFromString:obj1];
NSDate *date2 = [formatter dateFromString:obj2];
NSNumber *interval1 = [NSNumber numberWithDouble:abs([date1 timeIntervalSinceNow])];
NSNumber *interval2 = [NSNumber numberWithDouble:abs([date2 timeIntervalSinceNow])];
return (NSComparisonResult)[interval1 compare:interval2];
}];
And the closest date by,
NSString *closestDateString = [sortedArray objectAtIndex:0];
And from that,
int section = [keys indexOfObject:closestDateString];
NSIndexPath *scrollIndexPath = [NSIndexPath indexPathForRow:0 inSection:section];
Get the list of dates (from your dictionary or one you already have). Sort it. Loop over it (indexOfObjectPassingTest:) to find the date >= today (or use a predicate to filter and then take the first item from the result and get the index).
You have a sorted date array, don't you? Let's say it as dateArray.
Get today date object: NSDate * today = [NSDate date];
Search for dateArray to the nearest date, get the index of nearest date.
NSDate * today = [NSDate date] ;
__block NSUInteger section = NSNotFound ;
__block NSTimeInterval timeInterval = NSTimeIntervalSince1970 ;
[dateArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDate * date = obj ;
NSTimeInterval ti = [today timeIntervalSinceDate:date] ;
if (ti < 0)
ti = -ti ;
if (ti <= timeInterval) {
section = idx ;
timeInterval = ti ;
} else {
*stop = YES ;
}
}] ;
You know the section index now, let's say it as sectionIndex, the first row index in the section is 0.
So the NSIndexPath is [NSIndexPath indexPathForRow:0 inSection:sectionIndex]

Sorting NSArray by file creation time

I've read all answers about the subject, but still have my array unsorted. Please, help me with this issue. What's wrong with the code? Thanks in advance.
NSDictionary *attributes = [[NSFileManager defaultManager] attributesOfItemAtPath:filename error:NULL];
NSDate *date = [attributes fileCreationDate];
NSMutableArray *datesList = [[NSMutableArray alloc] init];
[datesList addObject:date];
NSArray *sortedArray = [[NSArray alloc] init];
sortedArray = [datesList sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2){
if ([obj1 date] > [obj2 date])
{
return (NSComparisonResult)NSOrderedAscending;
}
if ([obj1 date] < [obj2 date])
{
return (NSComparisonResult)NSOrderedDescending;
}
return (NSComparisonResult)NSOrderedSame;
}];
NSLog(#"sortedarray:%#",sortedArray);
First of all, you add to the array only one object :)
Your code should look like:
sortedArray = [datesList sortedArrayUsingComparator:^NSComparisonResult(NSDate *first, NSDate *second){
return [first compare:second];
}];
[NSDate compare:] returns `NSComparisonResult which is fine. You can add ! if you want to have opposite sorting direction.

Resources