vue：props中的值赋值给data

<template>
  <div>
    <navbar :ctype="ctype"></navbar>
  </div>
</template>
<script>
import navbar from '@/components/navbar'
   export default {
    components: {navbar},
    data () {
      return{
        ctype:1
      }
    }
   }
</script>

<template>
  <div>
    <div>{{thistype}}</div>
  </div>
</template>
<script>
export default {
    props:['ctype'],
    computed: {
      normalizedSize: function () {
        return this.ctype.trim().toLowerCase()
      }
    },
    data(){
        return{
            thistype:this.ctype
        }
    }
}
</script>