JavaScript - 复制对象数组并在不修改原始数组的情况下进行更改 [英] JavaScript - copy array of objects and make changes without modifying original array

问题描述

我有一个对象数组。我想深度复制对象数组并对每个对象进行一些更改。我想这样做而不修改原始数组或该数组中的原始对象。

I have an array of objects. I would like to deep copy the array of objects and make some changes to each object. I want to do this without modifying the original array or original objects that were in that array.

这就是我做的方式。但是，作为JavaScript的新手，我想确保这是一个很好的方法。

This is the way I have done it. However, being new to JavaScript I want to make sure this is a good approach.

有更好的方法吗？

const users = 
[
    {
        id       : 1,    
        name     : 'Jack',
        approved : false
    },
    {
        id       : 2,    
        name     : 'Bill',
        approved : true
    },
    {
        id       : 3,    
        name     : 'Rick',
        approved : false
    },
    {
        id       : 4,    
        name     : 'Rick',
        approved : true
    }
];


const users2 = 
    users
        .map(
            (u) => 
            {
                return Object.assign({}, u);
            }
        )    
        .map(
            (u) => 
            {
                u.approved = true;
                return u;
            }
        );    


console.log('New users2 array of objects:')
console.log(users2);

console.log('This was original users array is untouched:')
console.log(users);

输出：

New users2 array of objects:
[ { id: 1, name: 'Jack', approved: true },
  { id: 2, name: 'Bill', approved: true },
  { id: 3, name: 'Rick', approved: true },
  { id: 4, name: 'Rick', approved: true } ]
This was original users array is untouched:
[ { id: 1, name: 'Jack', approved: false },
  { id: 2, name: 'Bill', approved: true },
  { id: 3, name: 'Rick', approved: false },
  { id: 4, name: 'Rick', approved: true } ]

推荐答案

对于单次传递，您可以使用 Object.assign 以及更改后的属性。

For a single pass, you could use Object.assign with the changed property as well.

const users = [{ id: 1, name: 'Jack', approved: false }, { id: 2, name: 'Bill', approved: true }, { id: 3, name: 'Rick', approved: false }, { id: 4, name: 'Rick', approved: true }];
const users2 = users.map(u => Object.assign({}, u, { approved: true }));

console.log(users2);
console.log(users);

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