JavaScript __proto__ 会影响Object中原来的函数吗？

Question

函数getBooks已在Author.prototype中定义。但它不能在 Author 对象中使用。当我使用 __proto__ 继承 Person 属性时。为什么Author对象没有getBooks函数？是__proto__的效果吗？

function Person(name){
    this.name = name;
}
function Author(name,books){
    Person.call(this,name);
    this.books = books;
}
Person.prototype.getName = function(){
    return this.name;
}

Author.prototype.getBooks = function() {
    return this.books;
}

var john = new Person('John Smith');

var authors = new Array();

authors[0] = new Author('Dustin Diaz',['JavaScript Design Patterns']);
authors[1] = new Author('Ross Harmes',['JavaScript Design Patterns']);

authors[0].__proto__ = new Person();

console.log(john.getName());
console.log(authors[0].getName());
console.log(authors[0].getBooks())

Answer 1

__proto__ 是 deprecated 。相反，在向该类添加新的原型(prototype)方法之前，请将类的原型(prototype)分配给您尝试继承的类的新实例。

function Author(name, books) {
  Person.call(this, name);
  this.books = books;
}

Author.prototype = new Person();
Author.prototype.constructor = Author;

Author.prototype.getBooks = function() {
  return this.books;
};

JSFiddle 演示:https://jsfiddle.net/bkmLx30d/1/