ios - retain only unique values in array -

this question exact duplicate of:

• pulling unique values array of custom objects 1 answer

i have array of strings. need retain unique values, ie. want remove repititions. eg: if array {string1, string1, string1, string2, string3, string3} final array should {string1, string2, string3}

for(int p = 0; p < [allnewsdates count]; p++)     {         nslog(@"%@",allnewsdates[p]);         for(int q = p+1; q < [allnewsdates count]; q++)         {             nslog(@"%@   %@",allnewsdates[p],allnewsdates[q]);             if([allnewsdates[p] isequaltostring:allnewsdates[q]])             {                 flag = yes;                 t = q;                  break;              }         }         if(flag)         {             //[self.date addobject:alldates[p]];               [allnewsdates removeobjectatindex:p];             nslog(@"%i",[allnewsdates count]);         }          nslog(@"%i",p);         flag = no;     } 

i'm following above procedure extract unique dates array of dates. works ok. problem this: have news view controller shows news feed. if user selects news there, gets added favorites. if select news items in 1 go, favorites table shows news according date(different dates appear once 9th , 10th of may), if add news, go favorites, go news , click on news item(say 10th of may) , access favorites again, i'm getting 10th may twice. going wrong? please help!!

you can use kvc collection operators:

nsarray* uniquedates = [allnewdates valueforkeypath:@"@distinctunionofobjects.self"]  

more details here: http://www.nshipster.com/kvc-collection-operators