获取对象数组中每个用户的点赞总数 - JavaScript

Question

所以我遇到了一个逻辑问题。 我试图找出一种方法来获取对象数组中每个用户的喜欢总数。 这是我的示例数组。

const articles = [{
  authorId: "2vP3i2rYvDYPrikE1k1DTaZDeoq1",
  dislikes: 0,
  likes: 3,
  neutral: 0,
  text: "This is Mike Alice's first Shot!!",
  username: "mikealice",
  id: "NMFGbeTvSYddsr7VzjFV",
},
 {
  authorId: "2vP3i2rYvDYPrikE1k1DTaZDeoq1",
  dislikes: 0,
  likes: 2,
  neutral: 0,
  text: "This is Mike Alice's second Shot!!",
  username: "mikealice",
  id: "NMFGbeTvSYddsr7VzjFV",
},
 {
  authorId: "2vP3i2rYvDYPrikE1k1klkDTaZDeoq1",
  dislikes: 0,
  likes: 1,
  neutral: 0,
  text: "This is admin's first Shot!!",
  username: "admin",
  id: "NMFGbeTvSYddsr7VzjFV",
},
 {
  authorId: "2vP3i2rYvDYPrikE1k1klkDTaZDeoq1",
  dislikes: 0,
  likes: 3,
  neutral: 0,
  text: "This is admin's second Shot!!",
  username: "admin",
  id: "NMFGbeTvSYddsr7VzjFV",
}]

我的目标是有一个不同用户名的最终列表，他们的总喜欢如下一个。

const userLikes = [
  {
  username: 'mikealice',
  totalLikes: 5
  },
  {
  username: 'admin',
  totalLikes: 4
  }
]

帮我找出解决这个问题的逻辑。 谢谢。

Answer 1

1. 拿一个空物体，说obj
2. 循环遍历你的array
3. 在每个循环中，检查obj是否已经有一个与当前username相同的键
4. 如果没有，则创建一个键值对，键将是username ，值将是另一个包含username和totalLikes object
5. 如果已经有一个与username相同的键， totalLikes使用当前likes增加totalLikes的值
6. 循环完成后，您将得到答案，但以dictionary / object形式
7. Object.values将带出所需的array

代码 -

 let obj = {} articles.forEach((article, index) => { let { username, likes } = article if (!obj[username]) { obj[username] = { username, totalLikes: likes } } else { let { totalLikes } = obj[username] obj[username].totalLikes = totalLikes + likes } }) let finalArray = Object.values(obj)

Answer 2

使用reduce和Object.values会简化。

 const getTotalLikes = arr => Object.values( arr.reduce((acc, { username, likes }) => { acc[username] = username in acc ? { username, totalLikes: acc[username].totalLikes + likes } : { username, totalLikes: likes }; return acc; }, {}) ); const articles = [ { authorId: "2vP3i2rYvDYPrikE1k1DTaZDeoq1", dislikes: 0, likes: 3, neutral: 0, text: "This is Mike Alice's first Shot!!", username: "mikealice", id: "NMFGbeTvSYddsr7VzjFV" }, { authorId: "2vP3i2rYvDYPrikE1k1DTaZDeoq1", dislikes: 0, likes: 2, neutral: 0, text: "This is Mike Alice's second Shot!!", username: "mikealice", id: "NMFGbeTvSYddsr7VzjFV" }, { authorId: "2vP3i2rYvDYPrikE1k1klkDTaZDeoq1", dislikes: 0, likes: 1, neutral: 0, text: "This is admin's first Shot!!", username: "admin", id: "NMFGbeTvSYddsr7VzjFV" }, { authorId: "2vP3i2rYvDYPrikE1k1klkDTaZDeoq1", dislikes: 0, likes: 3, neutral: 0, text: "This is admin's second Shot!!", username: "admin", id: "NMFGbeTvSYddsr7VzjFV" } ]; console.log(getTotalLikes(articles));