将数组分配给对象

Question

我将我的应用从AngularJs迁移到Angular 4。

我在代码中经常使用以下类型的语句，因为它们在Angular 4（TypeScript）中都失败了：

编辑：在AngularJS中使用了以下行

var accomodation = {};
accomodation.AccomodationAddresses = [];

我在Angular4

中的类中尝试了这个

this.accomodation = {};
this.accomodation.AccomodationAddresses = [];

它给出错误：Property AccomodationAddresses不存在：（

Answer 1

Typescript使用赋值的推理来确定变量的类型。

你可以使用any来完全退出类型系统（不是一个很好的选择）：

let accommodation : any = {};
accomodation.AccomodationAddresses = [];

或者您可以明确指出变量的类型：

let accommodation : { AccomodationAddresses?: any[] } = {}; // used any but you can use a more explicit type
accomodation.AccomodationAddresses = [];

或使用命名界面：

interface Accomodation { AccomodationAddresses?: any[] } // used any but you can use a more explicit type
let accommodation : Accomodation  = {};     accomodation.AccomodationAddresses = [];

如果可行，您也可以一次初始化它并让TS推断出正确的类型：

let accomodation = { AccomodationAddresses: [] }