App.vue
InfoBox.vue
main.js
 
<template>
  <h2>Example $parent Object</h2>
  <p v-bind:style="{ backgroundColor: color }">The method that changes color can be reached directly from the child component by the use of the $parent object.</p>
  <div>
    <info-box />
  </div>
</template>

<script>
export default {
  data() {
    return {
      color: 'lightgreen'
    }
  },
  methods: {
    toggleColor() {
      if(this.color === 'lightgreen'){
        this.color = 'pink'
      }
      else {
        this.color = 'lightgreen'
      }
    }
  }
}
</script>                  
<template>
  <div>
    <h3>Toggle Color</h3>
    <p>Click the button to toggle the color in the P tag of the parent component.</p>
    <button v-on:click="this.$parent.toggleColor">Toggle</button>
    <p>The 'toggleColor' method is also in the parent component.</p>
  </div>
</template>

<style scoped>
div {
  border: solid black 1px;
  padding: 10px;
  width: 250px;
}
</style>                  
import { createApp } from 'vue'

import App from './App.vue'
import InfoBox from './components/InfoBox.vue'

const app = createApp(App)
app.component('info-box', InfoBox)
app.mount('#app')
                  
http://localhost:5173/