如何根据日期对响应数据进行排序

Question

I want to sort my UICollectionview data according to date...ie i want my UICollectionview cells position like First Come Last Serve....means the oldest date is at the last and the newest at the first...

{   data = (
                {
                   "news_date" = "2015-05-18 03:29:00";
                   "newslist_ID" = 1;
                   "title" = "title1";
                }, {
                   "news_date" = "2015-05-18 03:30:00";
                   "news_ID" = 2;
                   "title = "title2";
                }
            );
    "status" = "SUCCESS";
}

Above response i am trying to sort with "news_date" that is timestamp . I am trying to use sortedArrayUsingDescriptors ...but i have absolutely no idea how to use it properly....

Answer 1

If you are sorting dictionaries: ( However, I strongly advise against it. Transform your data to proper objects before working with them. )

NSArray* data = // array of dictionaries
NSArray* sortedData = [data sortedArrayUsingComparator:^NSComparisonResult(NSDictionary* obj1, NSDictionary* obj2) {
    NSDate* date1 = [obj1 objectForKey:@"news_date"]; // Date of obj1
    NSDate* date2 = [obj2 objectForKey:@"news_date"]; // Date of obj2

    return [date1 compare:date2];
}];

Answer 2

I'm more comfortable using closure-based sorting. You could use code like this:

array.sort
{
  $0["news_date" < $1["news_date"]
}

to sort a mutable array in place.

That code is sorting based on your current date strings. That should work based on the way your date strings are formed. You'd really be better off saving your date values as NSDates though.

EDIT:

That code won't work for NSMutableArrays.

If you're sorting NSMutableArrays the syntax would look like this:

var objCArray = [["key":"kumquat"],
  ["key": "orange"],
  ["key": "grape"],
  ["key": "apple"],
  ["key": "pear"],
  ["key": "mango"]] as NSMutableArray


objCArray.sortUsingComparator
  {
    (obj1, obj2) -> NSComparisonResult in
    let key1 = obj1["key"] as! String
    let key2 = obj2["key"] as! String
    return key1.compare(key2)
}

EDIT #2:

If you want to use sort descriptors, it would be better to sort your mutable array in place, rather than creating a new, immutable array like the code in @TejvanshSinghChhabra's answer, above. That code would look something like this:

var descriptor: NSSortDescriptor = NSSortDescriptor(
  key: "news_date", 
ascending: true) // or false, whichever suits you.
arrayNewslist.sortUsingDescriptors([descriptor]) //Sorts NSMutableArray in place 

Answer 3

You can try sorting the array using Sort Descriptor.

var descriptor: NSSortDescriptor = NSSortDescriptor(key: "news_date", ascending: true) // or false, whichever suits you.
var sortedResults: NSArray = results.sortedArrayUsingDescriptors([descriptor]) 

Hope it helps you to get desired result