如何获取父组件vueJs中的子组件数据？

<template>
  <div>
    <child-component :data="parentData"></child-component>
  </div>
</template>

<script>
export default {
  data() {
    return {
      parentData: 'Hello from parent'
    }
  }
}
</script>

<template>
  <div>
    <p>{{ data }}</p>
  </div>
</template>

<script>
export default {
  props: ['data']
}
</script>