Typescript界面中的可选字段

Question

On an Angular 7 project I have the following Typescript interface: 在Angular 7项目中，我具有以下Typescript接口：

export interface Request {
  expand: string;
  limit: number;
}

I then use it as follows: 然后，按如下方式使用它：

let request: Request = { expand: 'address' };

I get an error because I am not setting limit ... 我收到错误消息，因为我未设置limit ...

How can I make limit optional in the interface? 如何在界面中将limit可选？

Answer 1

Typescript 2.1 introduced Partial type : Typescript 2.1引入了Partial类型：

let request: Partial<Request> = { expand: 'address' };

Another way is to make the limit optional: 另一种方法是使limit可选：

export interface Request {
  expand: string;
  limit?: number;
}

Typescript界面​​中的可选字段