计算数组内部和数组中的数字？[重复]

Question

如何计算数组中数字的平均值？

看看我是如何获取数据的；

const reviews = [
0: ["5", "1"]
1: ["4"]
2:  ["1", "4", "1"]
3: ["1", "4"]
4:  ["5", "4"]
5: []
etc etc
]

我想知道每个阵列的平均值，所以：

0: 3
1: 4
2: 2 
etc etc

我在React工作。我从React Redux中的选择器获取数据。我用它来计算每个用户的平均评论。

代码：

  const reviews = users
    ? users.map((review) => {
        return review
          ? review.reviews.map((reviewen) => {
              return <p>{reviewen.review}</p>;
            })
          : "loading ";
      })
    : "Loading";

  console.log(reviews);

Answer 1

您可以使用. map和.减少：

const reviews = [
    ["5", "1"],
    ["4"],
    ["1", "4", "1"],
    ["1", "4"],
    ["5", "4"],
    [],
];

const averageReviews = reviews.map(
    (review) => review.reduce((total, rating) => total + rating, 0) / review.length
);

Answer 2

我想你正在寻找这样的东西：

const reviews = [
["5", "1"],
["4"],
["1", "4", "1"],
["1", "4"],
["5", "4"]
];
const avgReviews = reviews.map(x => (x.reduce((a,b) => parseInt(a) + parseInt(b), 0) / x.length));
console.log(avgReviews);