Javascript - 将对象添加到具有匹配 id 的数组

Question

我有一个数组categories，它的值为id，我试图将其与我的数组articles

匹配

如果 articles 有一个与 categories 之一匹配的 id，我想将它们组合成一个数组。我能够将这些对象添加到数组中，但它们不基于 id 进行匹配。

这是一个类别的例子:

const categories = [{results: 
    { 
      "id": 28,
      "name": "Articles"
    }, { 
      "id": 76,
      "name": "Projects"
    }
    }]

这里是一个文章的例子:

const articles = [ 
{
 "title": "first article",
 "content": "lorem ipsum",
 "categoryId": 28
},
{
 "title": "second article",
 "content": "lorem ipsum",
 "categoryId": 28
},
{
 "title": "thirdarticle",
 "content": "lorem ipsum",
 "categoryId": 76
},
]

我正在尝试将两个数组合二为一。如果可能的话，我希望 articles 数组是该匹配索引中的一个数组。例如:

 const combined = [
      {
        "id": 28,
        "name": "Articles",
        "articles:: [
          { "title": "first article", "content": "lorem ipsum", "categoryId": 28 },
          { "title": "second article", "content": "lorem ipsum", "categoryId": 28 },
        ],
      },
    ];

我尝试通过类别映射和使用 Object.assign 来实现这一点。输出结果似乎组合了数组，但我相信它们都是组合的并且与 id 不匹配。

我怎样才能做到这一点？

const articles = [ 
    {
     "title": "first article",
     "content": "lorem ipsum",
     "categoryId": 28
    },
    {
     "title": "second article",
     "content": "lorem ipsum",
     "categoryId": 28
    },
    {
     "title": "thirdarticle",
     "content": "lorem ipsum",
     "categoryId": 76
    },
    ]
    

const categories = {results: [{ "id": 28, "name": "Articles"}, {"id": 76, "name": "Projects"}]}

let combined = categories.results.map((item, i ) => Object.assign(item, articles));

  console.log(combined)

Answer 1

这是使用您的代码实现该目标的一种方法，但会过滤匹配的文章并使用 spread 运算符

let combined = categories.results.map(item => ({ ...item,
  articles: articles.filter(f => f.categoryId == item.id)
}));

const articles = [{
    "title": "first article",
    "content": "lorem ipsum",
    "categoryId": 28
  },
  {
    "title": "second article",
    "content": "lorem ipsum",
    "categoryId": 28
  },
  {
    "title": "thirdarticle",
    "content": "lorem ipsum",
    "categoryId": 76
  },
]


const categories = {
  results: [{
    "id": 28,
    "name": "Articles"
  }, {
    "id": 76,
    "name": "Projects"
  }]
}

let combined = categories.results.map(item => ({ ...item,
  articles: articles.filter(f => f.categoryId == item.id)
}));

console.log(combined)