javascript - 如何保存对象的初始语句？

Question

我有类型的对象:

export interface IGroupLanguage {
  name: string;
  languages?: Language[];
}

let data = [ { "name": "Automation", "languages": [ { "Name": "English", "Lcid": 1, "RightToLeft": true, "Code": "EN", "Mapped": true } ] }, { "name": "Monitors", "languages": [ { "Name": "Russian", "Lcid": 2, "RightToLeft": true, "Code": "RU", "Mapped": true } ] } ];

然后我尝试过滤对象并返回一个新对象:

 this.filteredObject = [...this.groups];
    this.filteredObject.map(item => {
      item.languages = item.languages.filter(
        lg =>
          lg.Name.toLocaleLowerCase().indexOf(searchQuery) != -1 ||
          lg.Code.toLocaleLowerCase().indexOf(searchQuery) != -1
      );
    });

问题是初始对象 this.groups 也被改变了。如何保存对象的初始语句？

结果我需要没有修改对象 this.groups 和过滤对象 this.filteredObject。

我知道问题是因为 JS 通过引用复制对象，但我不知道如何解决。

完整代码为:

search(searchQuery: string) {
    this.filteredObject = [...this.groups];
    this.filteredObject.map(item => {
      let tempLang = [...item.languages];
      item.languages = tempLang.filter(
        lg =>
          lg.Name.toLocaleLowerCase().indexOf(searchQuery) != -1 ||
          lg.Code.toLocaleLowerCase().indexOf(searchQuery) != -1
      );
    });

    console.log(this.groups);
  }


ngOnInit() {
    this.filteredObject = [...this.groups];
  }

结果初始对象 console.log(this.groups); 也被修改

Answer 1

因为你已经深度复制了数据的父数组而不是嵌套的数据，你能试试下面的方法吗-

this.filteredObject = [...this.groups];
    this.filteredObject.map(item => {
      let tempLang = [...item.languages];
      item.languages = tempLang.filter(lg =>
          lg.Name.toLocaleLowerCase().indexOf(searchQuery) != -1 ||
          lg.Code.toLocaleLowerCase().indexOf(searchQuery) != -1
      );
    });