javascript - 从数组数组中获取计数

Question

下面有一组数组。使用 ES6，我如何才能将每个值 Good、Excellent 和 Wow 计数到一个新数组中，例如 [{name:好，数:4} {name: Excellent, count: 5}, {name:Wow, count:2}] 动态风格。我正在尝试使用 Object.assign 但我无法“唯一”地计算出键的计数，相反，我需要使用一个数组，因为我试图在前端呈现它.我需要使用 reduce 吗？怎么办？

let k = 0
const stats = {}
const remarks = [
  [{name: "Good"}],
  [{name: "Good"}, {name: "Excellent"}],
  [{name: "Good"}, {name: "Excellent"}, {name: "Wow"}],
  [{name: "Good"}, {name: "Excellent"}, {name: "Wow"}],
  [{name: "Excellent"}],
  [{name: "Excellent"}]
]

remarks.forEach((arr) => {
  arr.map((e) => {
    Object.assign(stats, { [e.name]: k = k + 1 })
  })
})

console.log(stats);

输出:

stats: {Good: 8, Excellent: 11, Wow: 9}

这是不正确的，而且我需要使用数组。

预期输出:

[{name: Good, count: 4} {name: Excellent, count: 5}, {name:Wow, count:2}]

Answer 1

展平数组数组并从对象开始减少它，例如:{ Good: 0, Excellent: 0, Wow: 0}

然后 .map 结果的 Object.entries 将其转换为数组:

const remarks = [
  [{ name: "Good" }],
  [{ name: "Good" }, { name: "Excellent" }],
  [{ name: "Good" }, { name: "Excellent" }, { name: "Wow" }],
  [{ name: "Good" }, { name: "Excellent" }, { name: "Wow" }],
  [{ name: "Excellent" }],
  [{ name: "Excellent" }]
];

const result = Object.entries(
  remarks.flat().reduce(
    (all, { name }) => {
      all[name] += 1;
      return all;
    },
    { Good: 0, Excellent: 0, Wow: 0 }
  )
).map(([name, count]) => ({ name, count }));

console.log(result);