简单来说，$route.match包含从上到下的所有路由对象 (副本)。

一个例子：

路由配置：重点是meta标签

{
    path: '/livingData/personalTable',
    name: 'personalTable',
    component: RouteView,
    meta: { title: 'sideMenu.livingData.equipmentData', keepAlive: true, hidden: false, permission: ['table'] },
    redirect: '/livingData/personalTable/list',
    hideChildrenInMenu: false,
    children: [
      {
        path: '/livingData/personalTable/list',
        name: 'personalTable',
        hideChildrenInMenu: true,       //true => 在侧边菜单中隐藏子路由，即不显示下拉菜单
        component: () => import('@/pages/basicDataCol/lifeRecord/personalTable'),
        meta: { title: 'sideMenu.livingData.equipmentTable', keepAlive: true, hidden: false, permission: ['table']  },
        children: [
          {
            path: '/livingData/personalTable/detail',
            name: 'personInfo',
            component: () => import('@/pages/basicDataCol/lifeRecord/personalInfo'),
            hidden: true,               //不显示在侧边菜单中，与上面的配合使用
            meta: { title: 'sideMenu.livingData.detail', keepAlive: true, hidden: true, permission: ['table']  }
          },
        ]
      },
}

menu.js中菜单选择判断的函数

updateMenu () {
      const routes = this.$route.matched.concat()           //此处$route.matched
      console.log('routes =>',routes)                       //结果为 routes => (3) [{…}, {…}, {…}]
      console.log('meta.name =>',this.$route.meta.title)    //结果为 meta.name => sideMenu.livingData.detail
      console.log('meta.hidden =>',this.$route.meta.hidden) //结果为 meta.hidden => true
      //这三条信息可以看到，this.$route.matched包含了三层路由，目前的this.$route是最里面一层的路由
      
      if (this.$route.meta.hidden) {                        //如果当前路由的meta中hidden设为true
        routes.pop()                                        //就把这一层路由去掉
        //console.log('lengthFP =>',routes.length)          //结果为 lengthFP => 2
        this.selectedKeys = [routes.pop().path]             //选中上面pop完毕后的最后一层
        console.log('finish pop selectedKeys =>', this.selectedKeys) 
        //结果为 finish pop selectedKeys => ["/livingData/personalTable/list", __ob__: Observer]
      } else {
        console.log(routes.pop())
        this.selectedKeys = [routes.pop().path]             //如果meta中hidden设为false，就表示不‘隐藏’，直接选择最后一层路由即可
        console.log('no pop selectedKeys =>', this.selectedKeys)
      }

      const openKeys = []
      if (this.mode === 'inline') {
        routes.forEach(item => {
          openKeys.push(item.path)
        })
      }
      this.collapsed ? (this.cachedOpenKeys = openKeys) : (this.openKeys = openKeys)
    },