vue-router的router.go(n)问题？

<template>
  <div>

      <mt-navbar v-model="selected" class="container"  @click.native="goRouter">
        <mt-tab-item id="head-nav1">新歌</mt-tab-item>
        <mt-tab-item id="head-nav2">排行</mt-tab-item>
        <mt-tab-item id="head-nav3">歌单</mt-tab-item>
        <mt-tab-item id="head-nav4">歌手</mt-tab-item>
        <mt-tab-item id="head-nav5">彩铃</mt-tab-item>
      </mt-navbar>

  </div>
</template>

<script type="es6">
  import { Navbar, TabItem } from 'mint-ui';
  export default {
    name:'head-nav',
    data(){
      return {
        selected:'head-nav1'
      }
    },
    components:{Navbar, TabItem},
    methods:{
      goRouter(){
        var navItem=this.selected.charAt(this.selected.length-1);
        switch(navItem){
          case '1':this.$router.push({path:'index'});break;
          case '2':this.$router.push({path:'rank'});break;
          case '3':this.$router.push({path:'plist'});break;
          case '4':this.$router.push({path:'singer'});break;
          case '5':this.$router.push({path:'ringtone'});break;
        }
      }
    }
  }
</script>

回到上一级可以这么写

<template>
  <div class="rank-head container" :style="style">
    <a class="rank-head-back" @click="routerBack"></a>
    {{title}}
  </div>
</template>

<script type="es6">
  export default {
    props:['title','style'],
    name:'rank-head',
    methods:{
      routerBack(){
        this.$router.go(-1);
      }
    }
  }
</script>

这个demo的地址https://github.com/lavyun/vue-kugouMusic