title: Is FirebaseUser.getUid() constant for a given user?
body: <p>I have authenticated my user using phone authentication, and the user object that is returned has this long string when I call user.getUid() :</p>
  
  <p>dn27dhJK..... (some long string).</p>
  
  <p>If I authenticate this user on some other device (using my phone number etc), will user.getUid() always be the same ?</p>
  
  <p>EDIT: From the documentation: <a href="https://firebase.google.com/docs/reference/android/com/google/firebase/auth/FirebaseUser" rel="noreferrer">https://firebase.google.com/docs/reference/android/com/google/firebase/auth/FirebaseUser</a></p>
  
  <blockquote>
    <p>public abstract String getUid ()</p>
    
    <p>Also: Google Play services Returns a string used to uniquely identify
    your user in your Firebase project's user database. Use it when
    storing information in Firebase Database or Storage, or even in your
    own backend.</p>
    
    <p>This identifier is opaque and does not correspond necessarily to the
    user's email address or any other field.</p>
  </blockquote>
  
  <p>It is unclear if this id remains constant or not.</p>