怎么在一个函数里修改另外一个函数里的函数？

Question

假设我现在有一段代码function globalActions(){  App = function(obj) {    console.log('This is a global App, app id is ' + obj.id);  }  Page = function(obj) {    console.log('This is a global Page, page id is ' + obj.id);  }  App({id: 'app'});  Page({id: 'page'});  myGlobalActions();}function pluginActions(){  let originalMyPluginActions = myPluginActions;  myPluginActions = function(){    App = undefined    Page = function(obj) {      console.log('This is a plugin Page, page id is ' + obj.id);    }    originalMyPluginActions.apply(this, arguments);  }}function myGlobalActions(){  myPluginActions(App, Page);}function myPluginActions(){  let originalApp = arguments[0];  let originalPage = arguments[1];  arguments[0] = function() {    console.log('hello I try to modify the global App fn');    return originalApp.apply(this, arguments);  };  arguments[1] = function() {    console.log('hello I try to modify the global Page fn');    return originalPage.apply(this, arguments);  };}pluginActions();globalActions();在myGlobalActions里定义App或Page（App = / Page =）是禁止的，能够修改的只有myGlobalActions和myPluginActions，请问怎么才能修改globalActions里的App和Page？

Answer 1

如果是你提供的条件，那么是修改不了的，用术语说，这是 globalActions 函数的私有属性，外部是修改不了的。

Answer 2

动态更改一个块级作用域内部的变量，只能用闭包实现