[Vuejs]-Hiding Log Out Nav button on Log in page Vue JS

In your created method change to:

created () { 
  this.user = firebase.auth().currentUser || false;
}

Also make sure user is in your data method.

Then check user in your view.

<ul>
    ...
    <li v-if="user">Log Out</li>
    <li v-else>Register</li>
    ...
</ul>

As you go on, you want to abstract out the menu into a component so you’re not repeating this same code throughout each page.