javascript - 评估类构造函数中的参数

Question

在创建一个以对象作为参数的实例后，我想实现两件事:

首先，遍历参数的属性并将其添加到实例中，如果它与在构造函数上方声明的此属性方式完全相同。有没有一种快速的方法，我是否必须一项一项地检查？

其次，我想检查是否定义了每个声明的属性，如果没有定义则设置一个默认值。

var data = {
  langs: ["de","en","fr"],
  lesson: {
    de: "Einführung",
    en: "Introduction"
  },
  keywords: []
}

class Video {
  langs: Array<string>;
  lesson: object;
  topic: object;
  intro: object;
  keywords: Array<Keyword>;

  constructor (data) {
    for (let prop in data) {
      if (/*data.s is of type as declared above constructor()*/) {
        this[prop] = data[prop];
      } else {
        throw "Type of {{prop}} is invalid";
      }
    }
    for (let prop in /*All the props defined above constructor()*/) {
      if (!this.hasOwnProperty(prop)) {
        //Set default value;
      }
    }
  }
}

var video = new Video(data);

Answer 1

Is there a quick way to do so are do I have to check this one by one?

使用类型注释，例如改变

constructor (data) {

到

constructor (data: { langs : string[] /* so on */}) {

i want to check if each of the declared properties is defined and set a default value if not.

使用 strictNullChecks 将逻辑移出代码:https://basarat.gitbooks.io/typescript/content/docs/options/strictNullChecks.html