如何使用javascript通过分类获得总星数？ [复制]

Question

我没有找到任何解决方案。

假设，这里是一个数组

[
  {name: "one", rating: 2}
  {name: "anything", rating: 1}
  {name: "two", rating: 4}
  {name: "red", rating: 2}
  {name: "helpme", rating: 2}
  {name: "jiue", rating: 4}
  {name: "one", rating: 1}
  {name: "one", rating: 2}
]

在这里，我必须找到评分 1、2、3、4、5 的总数

在数组中-

我们可以看到

oneStar = 2 times
twoStar = 4 times
threeStar = 0 Times 
fourStar = 2 times
fiveStar = 0 times

我必须使用 javascript 来返回它-

oneStar = 2
twoStar = 4
threeStar = 0
fourStar = 2
fiveStar = 0

Answer 1

您可以使用Array#reduce 和一个数组来存储每个评分的频率。

let arr = [
  {name: "one", rating: 2},
  {name: "anything", rating: 1},
  {name: "two", rating: 4},
  {name: "red", rating: 2},
  {name: "helpme", rating: 2},
  {name: "jiue", rating: 4},
  {name: "one", rating: 1},
  {name: "one", rating: 2}
];
let ratingFreq = arr.reduce((acc, curr)=>(++acc[curr.rating - 1], acc), 
                    Array(5).fill(0));
console.log(ratingFreq);