可选链操作符

 "@babel/plugin-proposal-optional-chaining": "^7.16.7",
 
 //vue插件
 const chaining = {
  install(vue) {
    const variableOptional = (target) => {
      return new Proxy(target, {
        get: (target, propKey) => {
          const proKeyArr = propKey.split('?.')
          return proKeyArr.reduce((a, b) => a?.[b], target)
        },
      })
    }
    // 添加实例方法
    vue.prototype.$chaining = variableOptional
  },
}

export default chaining

//main.js中
import chaining from '@/plugins/chaining'
Vue.use(chaining)