长数组的对象解构解决方案? [英] Object destructuring solution for long arrays?

问题描述

看这段代码:

let lecture = {
  id: 2,
  title: "MyTitle",
  topics: [
    {
      title: "John",
      age: 1
    },
    {
      title: "John2",
      age: 2
    },
    {
      title: "John3",
      age: 3
    }
  ]
}

我想提取数组中的主要title属性和第三个age(通过对象解构)

I want to extract the main title property and the third age in the array (via object destructuring)

我可以通过 :

let { title:lectureTitle , topics:[,,{age:thirdAge}]} = lecture;
console.log(lectureTitle,thirdAge);//MyTitle 3

问题

但是如果数组有 100 个项目并且我想要第 99 个 age 怎么办?

But what if the array has 100 items and I want the 99'th age ?

那我该怎么做呢?对象解构是否为此提供了解决方案?

How would then I do it ? Does object destructuring offer a solution for that?

推荐答案

但是如果数组有 100 个项目并且我想要第 99 个年龄怎么办?

But what if the array has 100 items and I want the 99'th age ?

数组是对象，所以这样做:

Arrays are objects, so this will do:

let {title: lectureTitle, topics: {98: {age: thirdAge}}} = lecture;

<小时>

注意 然而，[...] 类型的解构适用于任何可迭代对象，而 {...} 仅适用于对象(以及数组).要使上述解决方案适用于任意可迭代对象，您必须展开可迭代对象并将其用数组包装.

---

Note however that the [...] type of destructuring works with any iterable, whereas {...} only works with objects (and therefore arrays). For the above solution to work with arbitrary iterables you will have to spread the iterable and wrap it with an array.

let {title: lectureTitle, topics: {98: {age: thirdAge}}} = [...lecture];

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