ios - Passing in ivar into method Swift -

i making simple reminder app in swift , i'm having hard time figuring out why can't method compile.

 reminder in self.reminders {              if dates.contains(dateformatter.stringfromdate(reminder.date)) {                 dates.add(reminderdate)             }  } 

on call stringfromdate getting error saying

"cannot invoke "stringfromdate" argument list of type (nsdate?!)"

the date ivar nsdate, need able call it?

i declare property var date: nsdate

declaration property var reminders = []

class trreminder {          enum trpriority {             case low, medium, high         }          var title: string         var date: nsdate         var location: string         var priority: trpriority         var note: string           init(title: string, date: nsdate, location: string, priority: trpriority, note: string) {              self.title = title             self.date = date             self.location = location             self.priority = priority             self.note = note          }      } 

do this

var reminders = [trreminder]() 

declaring [] is, believe, equivalent [anyobject?]