VueJS Form Input Binding

computed: {
    lastName: {
        get(){
            //perform your logic
            return 'value.second'
        },
        set(newValue){
            this.value.second = newValue;
        }

    } 
  }     

<input type="text" v-model="lastName" placeholder="Enter last name" />

det (param) {
    let strlen = param.length
        if(1 === strlen){
    return param
  }
  let split = param.split('.')

  let details = JSON.parse(JSON.stringify(this.details))
  for (var key in details) {
    if(key == split[0]){
      for (var key2 in details[key]) {
       return details[key][key2]
      }
    }
  }
}

this.form[`comp_${c}`] = parseFloat(a) / parseFloat(b);

Vue.set(this.form, `comp_${c}`, parseFloat(a) / parseFloat(b));

<template> 
  <div> 
    <label for=""> Employee </label>
    <input class="form-control-plaintext" :value="showAssignedUser()" type= "text" readonly name="surname">
  </div>
</template>

<script> 
  data(){
    return:{
      asset:{},
    }
  },

  methods:{
     getAsset(){
        axios.get('/api/assets/'+this.id)
          .then ( response => {
            this.asset = response.data.data[0].data; 
            this.toFill = this.asset()
            this.assetForm.fill(this.toFill)
           })
        },

    showAssignedUser(){
        return `${this.asset.current_status.user.surname}` + ' '+ `${this.asset.current_status.user.first_name}`
    },

  },

  mounted(){
     this.getAsset();
 }
</script>