快速解析firebase时为零

Question

I am trying to parse value from firebase to my dictionary:

for rest in snapshot.children.allObjects as! [FIRDataSnapshot] {

                guard let restDict = rest.value as? [String: String] else {
                    continue
                }
                if (restDict["uid"] != FIRAuth.auth()?.currentUser?.uid && (restDict["userCity"])! == "SomeCity"){

                    self.users.updateValue(restDict["userImgLink"]!, forKey: restDict["userName"]!)
                        print(self.users["userName"])

                    }
            }

And here is my dict declaration:

var users: [String : String] = [:]

restDict value returns me an Optional("somestring"), but elf.users["userName"] returns nil. How could I get a real value in my dict? Thanks in advance.

Answer 1

In the below line you are trying to set the value restDict["userImgLink"]! for key restDict["userName"]! , so the key will be the value of restDict["userName"]! and not "userName" .

 self.users.updateValue(restDict["userImgLink"]!, forKey: restDict["userName"]!)

but while printing you are trying to get the value for "userName" key , which will be nil.