How to use value from data() of one component in another vue?

Question

Vue.js

There is a component ( toolbar ) to which you need to pass a value from another component ( B ), but component B is essentially a page that is loaded when you follow the links of the router
. Here is the structure

<template>
  <v-app>
    <v-content>
        <Toolbar />

        <Drawer />

        <nuxt />
    </v-content>
  </v-app>
</template>

<script>
import Toolbar from '~/components/core/Toolbar.vue'
import Drawer from '~/components/core/Drawer.vue'

export default {
  components: {
    Toolbar,
    Drawer
  }
}
</script>

( <nuxt /> = <router-view />)
How do I get the title value that is contained in the component

index.vue (main page)

export default {
data: () => ({
title: 'Vuetify.js',
})
}

in the toolbar for further use?

Answer 1

https://ru.vuejs.org/v2/guide/state-management.htm...