title: Default value v-model data
body: <p>Is it possible to assign a default value to data?
  lastName, firstName and avatar are each assigned to my form with v-model.
  I need this to modify the user's profile, in order to avoid errors like undefined if he does not fill in the whole form.</p>
  <p>it gives me error it can't find user, i don't know how to assign user to my data</p>
  <pre><code>export default {
    name: &quot;ProfilC&quot;,
    data: function () {
      return {
        lastName: user.user_lastName,
        firstName: user.user_firstName,
        avatar: user.user_avatar,
      };
    },
  computed: {
      ...mapState({
        user: &quot;userInfos&quot;,
      }),
    },
  </code></pre>