Sort NSArray by 'Date' Element of included NSDictionaries - objective-c

Question

Here's what I have:
An NSMutableArray that holds several NSDictionary Objects.
Each NSDictionary has a Date String as an Element.
Here's my loop that prints out the Date in each NSDictionary
[dateFormatterIn setDateFormat:#"yyyyMMddHHmmss\n"];
[dateFormatterOut setDateFormat:#"dd.MM.yyyy"];
for(NSMutableDictionary *thisStory in stories){
id fromDate = [thisStory objectForKey:#"from_time"];
id date = [dateFormatterIn dateFromString:fromDate];
NSLog(#"%#", [dateFormatterOut stringFromDate:date]);
}
Does anyone have a clue how I can sort my array stories by date?
I am quite new to objective C.
Thanks in advance!

Answer 1

Using the your stories array's sortUsingDescriptor method should do the trick:
NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey: #"from_time" ascending: YES] autorelease];
[stories sortUsingDescriptors: [NSArray arrayWithObject: sortDescriptor]];

Answer 2

Let's assume Following data structure : array variable name: collectionArray =
[
{
date: "01-02-2015 02:01",
value: 1,
name: "rajan"
},
{
date: "01-02-2014 02:01",
value: 11,
name: "rajan1"
},
{
date: "01-02-2012 02:01",
value: 111,
name: "rajan2"
}
]
Now to sort this array of nsdictionary by date we follow the following steps
`NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy HH:mm"];
NSMutableArray *sortedArray = [[collectionArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *obj1, NSDictionary *obj2) {
NSString *d1Str =[obj1 valueForKey:#"date"];
NSString *d2Str =[obj2 valueForKey:#"date"]
NSString *d1Timestamp = [NSString stringWithFormat:#"%f", [[formatter dateFromString:d1Str] timeIntervalSince1970]];
NSString *d2Timestamp = [NSString stringWithFormat:#"%f", [[formatter dateFromString:d2Str] timeIntervalSince1970]];
return [d2Timestamp compare:d1Timestamp options:NSNumericSearch]; // descending order
}] mutableCopy];`