javascript - 我如何用JS计算json文件中的相同值

这是我的json文件的一部分

     {
      "articles": [
        {
          "rank": "1",
          "title": "Harvard University",
          "country": "USA",
          "score": "100.00"
        },
        {
          "rank": "3",
          "title": "Massachusetts Institute of Technology",
          "country": "USA",
          "score": "97.12"
        },
        {
          "rank": "5",
          "title": "University of Oxford",
          "country": "United Kingdom",
          "score": "95.39"
        },
        {
          "rank": "36",
          "title": "École Polytechnique",
          "country": "France",
          "score": "59.09",
        },
        {
          "rank": "904",
          "title": "University of Basilicata",
          "country": "Italy",
          "score": "44.31",
        }
        ]
    }

我想计算用于制作Google图表的JS功能的相同国家/地区的数量。我需要这样的结果：
country:{"USA" : 57,"Japan" : 23,"United Kingdom" : 38,"

另一个函数将返回分数大于80且小于80的大学的数量，如下所示：
score:{"morethan80" : 195,"lessthan80" : 805,"

最佳答案

您需要做的是遍历地图，检查是否符合您的条件，如果符合，则增加它。

通常，reduce在输入和输出中获取所需的数组：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce

const output = data.articles.reduce(
  (result, article) => ({
    country: {
      ...result.country,
      [article.country]: result[article.country] ? result[article.country] + 1 : 1,
    },
    score: {
      morethan80: parseInt(article.score) >= 80 ? result.morethan80 + 1 : result.morethan80,
      lessthan80: parseInt(article.score) < 80 ? result.lessthan80 + 1 : result.lessthan80,
    }
  }),
  { country: {}, score: { morethan80: 0, lessthan80: 0 }}
);

告诉我您是否需要更多答案的详细信息。

关于javascript - 我如何用JS计算json文件中的相同值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47100078/