javascript - 如何使用 javascript 对象中的构造函数来仅使用 `this` 中的属性？

Question

我想创建以下类的实例:

class Person {
    firstName;
    lastName;
    birthday;
    constructor(props: Person) {
        {firstName,lastName,birthday} = props
    }
}

var me = new Person({firstName: "donald", 
lastName: "trump",
 middleName: "john"})

我希望构造函数只选择要分配给“this”的类的属性，这样 me 将是 {firstName: "donald", lastName: "trump ", 生日:未定义

我的想法是:

class Person {
    firstName;
    lastName;
    birthday;
    constructor(props: Person) {
        this.{firstName,lastName,birthday} = props
    }
}

var me = new Person({firstName: "donald", lastName: "trump", middleName: "john"})

或类似的东西。

Answer 1

您可以分两行执行此操作:

const {firstName,lastName,birthday} = props;
Object.assign(this, {firstName,lastName,birthday});

现在，如果这只是关于三个 属性，只需执行:

this.firstName = props.firstName;
this.lastName = props.lastName;
this.birthday = props.birthday;

它更具可读性，而且速度稍快。值得额外排队。

您还可以更改构造函数签名，以便它解构所需的属性:

constructor({firstName: string, lastName: string, birthday: Date}) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.birthday = birthday;
}