在ES6中创建多个构造函数

ECMAScript不支持函数/构造函数重载。如果您还想破解arguments对象,可以使用它。

constructor(title, length, author) {
        if(!arguments.length) {
            // empty book
        }
        else {
            this.title = title;
            this.Length = length;
            this.author = author;
        }
    }

实际上,确实可以为一个原型创建多个构造函数。你只要看看 constructor 原型的属性 is not special . 因此,可以创建多个构造函数,如下所示:

const type = (prototype, constructor) =>
    (constructor.prototype = prototype, constructor);

const book = {
    flipTo(page) {
        this.page = page;
    },
    turnPageForward() {
        this.page++;
    },
    turnPageBackward() {
        this.page--;
    }
};

const EmptyBook = type(book, function EmptyBook() {
    this.constructor = EmptyBook;
    this.ISBN        = "";
    this.title       = "";
    this.author      = "";
    this.genre       = "";
    this.covering    = "";
    this.length      = -1;
    this.page        = 0;
});

const Book = type(book, function Book(title, author, length) {
    this.constructor = Book;
    this.ISBN        = "";
    this.title       = title;
    this.author      = author;
    this.genre       = "";
    this.covering    = "";
    this.length      = length;
    this.page        = 0;
});

只需给构造函数起不同的名字。希望能有所帮助。