typescript - 如何在 typescript 中创建对象时通过传递JSON来初始化构造函数参数

Question

假设我有一个类

export class PersonName {
    constructor(
        public firstName: string = "",
        public lastName: string = "",
        public middleName: string = "",
    ) { }
}

我想通过在创建对象时传递 json 对象来初始化在构造函数中声明的这些变量。

例如:

var person = new Person({
        "firstName"  : "abc",
        "lastName"   : "xyz",
        "middleName" : ""
       });

Answer 1

一种方法是为构造函数提供重载，然后测试第一个参数是字符串还是包含字段的对象:

export class Person {
  public firstName;
  constructor(
      firstName: string,
      lastName: string,
      middleName: string,
  );  
  constructor(
      person: { firstName: string, lastName: string, middleName: string }
  );  
    constructor(
        arg1: string | { firstName: string, lastName: string, middleName: string } = "",
        public lastName: string = "",
        public middleName: string = "",
    ) {
      if (typeof arg1 === "string") {
        this.firstName = arg1;
      } else {
        this.firstName = arg1.firstName;
        this.lastName = arg1.lastName;
        this.middleName = arg1.middleName;
      }
    }
}

const person = new Person({
        "firstName": "",
        "lastName": "",
        "middleName": "",
 });
 const person2 = new Person("foo", "bar", "baz");