我怎样才能计算与JS的json文件相同的值

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", } ] } 

我想统计与谷歌图表的JSfunction相同的国家的数量。 我需要这样的结果： country:{"USA" : 57,"Japan" : 23,"United Kingdom" : 38,"

而另一个函数将会返回分数大于80且小于80的大学数，如下所示： score:{"morethan80" : 195,"lessthan80" : 805,"

Answer 1

你需要做的是循环浏览地图，检查它是否符合你的条件，如果是的话，增加它。

通常， reduce可以在input和输出中使用任何数组： 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，如果你需要更多的答案细节。