UID doesn't show out of constructor

Question

I have some problems trying to get the uid out of my constructor. When i run this code the uid shows perfectly in the Test 1 log. However the Test2 log shows its undefined. Does the uid deletes himself when the constructor closes?

import { Component, OnInit } from '@angular/core';
import {AngularFire, FirebaseObjectObservable, FirebaseListObservable} from 'angularfire2';

@Component({
  selector: 'dashboard',
  templateUrl: 'dashboard.component.html',
  styleUrls: ['./dashboard.component.css']
})
export class DashboardComponent {
  userid:string;
  users:FirebaseListObservable<any[]>;
  constructor(public af: AngularFire) {
    this.af.auth.subscribe(auth => {
      console.log(auth.uid);
      this.userid = auth.uid;
      console.log("Test 1 "+ this.userid);
    });
    console.log("Test2 "+ this.userid);
  }
}

this is my output in my console

Angular 2 is running in the development mode. Call enableProdMode() to enable the production mode.
dashboard.component.ts:18 Test2 undefined
dashboard.component.ts:14 CgTltJ1h2TUFS5teoACCxoPHP1g1
dashboard.component.ts:16 Test 1 CgTltJ1h2TUFS5teoACCxoPHP1g1

My second question is how can i get the uid out of my constructor? Cause i need it to get some othre data from the database.

Answer 1

When console.log("Test2...") is executed the value is not yet available

When the data arrives from the server the function passed to subscribe()

    auth => {
      console.log(auth.uid);
      this.userid = auth.uid;
      console.log("Test 1 "+ this.userid);
    }

is called, only then the data becomes available and only within that function, console.log("Test2 ...") was executed a looong time before that

export class DashboardComponent {
  userid:string;
  users:FirebaseListObservable<any[]>;
  constructor(public af: AngularFire) {
    this.af.auth.subscribe(auth => {
      console.log(auth.uid);
      this.userid = auth.uid;
      console.log("Test 1 "+ this.userid);
    });
    console.log("Test2 "+ this.userid);
  }
}