vue如何获取下拉列表对应的id？

Question

<select class="form-control" v-model="aaa">

<option v-for="RoleItem in list_roleName" value=RoleItem.id>{{RoleItem.name}}</option>

</select>
{{aaa}}

数据如下

如果用户选中了BD，则aaa的数据为3，这该怎么弄啊

Answer 1

<select class="form-control" v-model="aaa">

<option v-for="RoleItem in list_roleName" :value=RoleItem.id>{{RoleItem.name}}</option>
</select>

Answer 2

https://codesandbox.io/s/nr43...

Answer 3

<div id="app">
  <h2>Todos:</h2>
  <select class="form-control" v-model="selectId">
<option v-for="RoleItem in todos" :value=RoleItem.id>{{RoleItem.text}}</option>
</select>
<div>
当前选择值 ：{{selectId}}
</div>

</div>

new Vue({
  el: "#app",
  data: {
    selectId:'',
    todos: [
      { text: "Learn JavaScript", done: false,id:1 },
      { text: "Learn Vue", done: false,id:2 },
      { text: "Play around in JSFiddle", done: true,id:3 },
      { text: "Build something awesome", done: true,id:4 }
    ]
  },
  methods: {
  }
})