如何获取javascript对象属性的子集 [英] How to get a subset of a javascript object's properties

问题描述

说我有一个对象：

elmo = { 
  color: 'red',
  annoying: true,
  height: 'unknown',
  meta: { one: '1', two: '2'}
};

我想用一个属性的子集创建一个新对象。

I want to make a new object with a subset of its properties.

 // pseudo code
 subset = elmo.slice('color', 'height')

 //=> { color: 'red', height: 'unknown' }

我如何实现这一目标？

推荐答案

使用对象解构和属性速记

Using Object Destructuring and Property Shorthand

const object = { a: 5, b: 6, c: 7  };
const picked = (({ a, c }) => ({ a, c }))(object);

console.log(picked); // { a: 5, c: 7 }

来自Philipp Kewisch：

From Philipp Kewisch:

这实际上只是一个即时调用的匿名函数。所有这些都可以在解构分配 MDN上的页面。这是一个扩展形式

This is really just an anonymous function being called instantly. All of this can be found on the Destructuring Assignment page on MDN. Here is an expanded form

let unwrap = ({a, c}) => ({a, c});

let unwrap2 = function({a, c}) { return { a, c }; };

let picked = unwrap({ a: 5, b: 6, c: 7 });

let picked2 = unwrap2({a: 5, b: 6, c: 7})

console.log(picked)
console.log(picked2)

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