vue判断是新增还是修改

{
        path: ‘save‘,
        name: ‘添加讲师‘,
        component: () => import(‘@/views/edu/teacher/save‘),
        meta: { title: ‘添加讲师‘, icon: ‘tree‘ }
      }

<router-link :to="‘/teacher/edit/‘+scope.row.id">
    <el-button type="primary" size="mini" icon="el-icon-edit">修改</el-button>
</router-link>

created(){
    this.init()
  },
  watch:{
    $route(to,from){
      this.init()//监听路由的变化
    }
  },methods:{
    init(){
      //根据路由和id的值判断是新增还是修改
      if (this.$route.params && this.$route.params.id) {
          //修改，对象初始化
        const id = this.$route.params.id
        this.getInfo(id)//调用对象初始化方法，给对象赋值
      }else{
          //新增，清空对象
        this.teacher = {}
    }
    },

  }