ios - Swift 3 numberOfRows table view function error -


i'm having issue trying use value return numberofrows function table view. in viewdidload have code below , prints value need, when try return same variable says found nil when unwrapping value. suggestions?

let prevorderref = ref?.child("users").child(currentuserid!).child("previous orders")      prevorderref?.observesingleevent(of: .value, with: { (snapshot) in          let dict = previousorders(snapshot: snapshot)         self.prevordercount = dict.prevordersdict?.count         print(self.prevordercount!)      })

update:

func tableview(_ tableview: uitableview, numberofrowsinsection section:            int) -> int {     if tableview == self.currentordertblview {          return 1     } else {          let prevorderref = ref?.child("users").child(currentuserid!).child("previous orders")          prevorderref?.observesingleevent(of: .value, with: { (snapshot) in               let dict = previousorders(snapshot: snapshot)             self.prevordercount = dict.prevordersdict?.count             print(self.prevordercount!)            })          return 2     }   }

i have moved firebase database data observe inside numberofrows. prints value needed still unable use return.

remove ! return statement

func tableview(_ tableview: uitableview, numberofrowsinsection section: int) -> int  {    if tableview == self.currentordertblview    {     return 1    }    else   {     return self.prevordercount   } }

declare variabe as

 var prevordercount: int!

also initialize in viewdidload as

  self.prevordercount=0 // 0 or wanted default

these optionals assumed contain value. therefore whenever access implicitly unwrapped optional, automatically force unwrapped you. if doesn’t contain value, crash.

make sure have assigned value


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