javascript - 如何让每个实例继承自己的成员实例？

Question

在下面的代码中，我有两个 Book Collections。一个系列有“Moby Dick”，而另一个系列有“The Firm”。但是，当我看第二集时，它也有白鲸记。如何创建不共享相同数据的书籍？

function Collection () {
    var stuff = [];
    this.get = function () {
        return stuff;
    };
    this.add = function (item) {
        stuff.push(item);
    };
}
function Books () {}
Books.prototype = new Collection ();

var myBooks = new Books();
myBooks.add("Moby Dick");

var yourBooks = new Books();
yourBooks.add("The Firm");

console.log(yourBooks.get()); // ["Moby Dick", "The Firm"]

我最终选择了这个:

function Collection () {
    var stuff = [];
    this.get = function(){
        return stuff;
    };
    this.add = function(item){
        stuff.push(item);
    };
}
function Books () {
    Collection.call(this);
};

Books.prototype = new Collection();

Books.prototype.constructor = Books;

var myBooks = new Books();
myBooks.add("Moby Dick");

var yourBooks = new Books();
yourBooks.add("The Firm");

console.log(myBooks.get());

Answer 1

在 this 中使用每个实例的值:

function Books () {
    this.stuff = [];
}

然后在集合中:

this.get = function () {
    return this.stuff;
};

目前只有一个stuff数组是在设置Books的原型(prototype)时创建的。然后所有继承的 getter 和 setter 都引用那个变量。

---

Complete code :

function Collection () {
    this.get = function () {
        return this.stuff;
    };
    this.add = function (item) {
        this.stuff.push(item);
    };
}
function Books () {
    this.stuff = [];
}

Books.prototype = new Collection ();

var myBooks = new Books();
myBooks.add("Moby Dick");

var yourBooks = new Books();
yourBooks.add("The Firm");

console.log(myBooks.get()); // ["Moby Dick"]
console.log(yourBooks.get()); // ["The Firm"]