Javascript - 如何在方法中获取/设置？（例如菠萝.is_a.fruit）

Question

我有一项任务，要求我通过编程创造奇迹。我无法在网上找到任何答案，因为我不知道它的搜索词（尝试过方法中的方法等...）。感谢所提供的任何帮助！这就是我得到的：我需要创建一个基于自身构建的类。例如const pineapple = new Item('pineapple');pineapple.type = fruit // this is simplepineapple.is_a.fruit = true // this I do not knowpineapple.is.heavy = true // same thing我什至不知道从哪里开始。我的尝试与此类似，但我变得不确定。class Thing {  constructor(type) {    this.type = type;  }    is_a(bool) {    this.fruit = this.is_a(bool);  }}

Answer 1

假设它们可以提前定义，为了拥有像 的子属性pineapple.is_a.fruit，您需要在对象的is_a和is属性上定义对象。例如（见评论）：

class Item { // `Item` rather than `Thing`, right?

    constructor(type) {

        this.type = type;

        // Create an `is_a` property that's an object with a `fruit` property

        this.is_a = {

            fruit: false // Or whatever the initial value should be

        };

        // Create an `is` property that's an object with a `heavy` property

        this.is = {

            heavy: false // Or whatever the initial value should be

        };

    }

}

const pineapple = new Item('pineapple');

pineapple.type = "fruit"; // I added quotes here

console.log("is_a.fruit before:", pineapple.is_a.fruit);

console.log("is.heavy before:", pineapple.is_a.fruit);

pineapple.is_a.fruit = true;

pineapple.is.heavy = true;

console.log("is_a.fruit after: ", pineapple.is_a.fruit);

console.log("is.heavy after: ", pineapple.is_a.fruit);