如何将基本数据保存到数组中-HowtosaveFirebaseDataintoanArray

I have a Firebase database that is modeled as such:

我有一个这样建模的Firebase数据库:

: users
    : some-random-id-1
        - username:"user1"
        - email:"email1@gmail.com"
    : some-random-id-2
        - username:"user2"
        - email:"email2@gmail.com"

I am trying to iterate through all the users in the dictionary of data and append the username into a list in the file to be used for other purposes. I created a string array (userslist) variable and in viewdidload(), I wrote the following code below:

我尝试遍历数据字典中的所有用户，并将用户名附加到文件中的列表中，以便用于其他目的。我创建了一个字符串数组(userslist)变量，在viewdidload()中，我编写了以下代码:

    ref = Database.database().reference()
    ref?.observe(.value, with: { (snapshot) in
        let dataDict = snapshot.value as! NSDictionary
        let x = dataDict["users"] as! NSDictionary
        print(x)
        print("--------")
        for user in x{
            let y = user.value as? [String: String]
            let z = y!["username"]
            print(z)
            self.userslist.append(z!)
            print(self.userslist)
            print("NEXT")
        }
    })
    print(self.userslist)

Inside the brackets of the snapshot, when I print self.userslist, I can see that each element is getting added, but when I print it a final time outside of the brackets, it shows it as an empty array. I think that the elements are only appended in the scope of those brackets so I cant access the filled array anywhere else. How do I get around this so I can use the data I appended?

在快照的括号内，打印self。userslist，我可以看到每个元素都被添加了，但是当我最后一次在括号外打印时，它显示为一个空数组。我认为这些元素只添加在括号的范围内，所以我无法访问填充数组。如何绕过这个，以便使用我添加的数据?

1 个解决方案

    ref?.observe(.value, with: { (snapshot) in
            let dataDict = snapshot.value as! NSDictionary
            let x = dataDict["users"] as! NSDictionary
            print(x)
            print("--------")
            for user in x{
                let y = user.value as? [String: String]
                let z = y!["username"]
                print(z)
                self.userslist.append(z!)
                print(self.userslist)
                print("NEXT")
            }
            /// Here is your data
            print(self.userslist)
        })
 /// Called before Handler execution
 print(self.userslist)