一旦用戶登錄，我就通過權限過濾菜單數組。我生成靜態菜單，然后將數組的副本提供給過濾器。constructor(public menu: MenuService, public permissionService: PermissionService) {    console.log(menu.getMenu()) // this changes after filtering below    this.menuItems = this.permissionService.filterMenuByTopic([...menu.getMenu()]); // here I'm using a copy  }為什么會出現這種情況呢？如果我使用了擴展運算符并且不使用原始數組[...menu.getMenu()]。僅當我刷新頁面時才menu.getMenu()返回原始值UPD 1回答評論，這里是 getMenu() 函數import { Injectable } from '@angular/core';@Injectable()export class MenuService {  menuItems: Array<any>;  constructor() {    this.menuItems = [];  }  addMenu(items: Array<{    text: string,    heading?: boolean,    link?: string,     // internal route links    elink?: string,    // used only for external links    target?: string,   // anchor target="_blank|_self|_parent|_top|framename"    icon?: string,    alert?: string,    submenu?: Array<any>  }>) {    items.forEach((item) => {      this.menuItems.push(item);    });  }  getMenu() {    return this.menuItems;  }}