javascript - 通过在 JSON 数据中查找值来创建新的对象数组

Question

不确定我能否做到这一点，但我正在尝试做的是通过搜索一些 JSON 数据来找到一个键并在找到该键时将整个对象放入新数组来创建一个新数组。以下是我正在使用的数据示例。

{
  "students": {
    "AB10001": {
      "campus": "cda",
      "subjects": ["history", "english"],
    }
    "AB10002": {
      "campus": "asd",
      "subjects": ["maths"],
    }
    "AB10003": {
      "campus": "asd",
      "subjects": ["english"],
    }
    "AB10004": {
      "campus": "asd",
      "subjects": ["history"],
    }
    "AB10005": {
      "campus": "cda",
      "subjects": ["maths", "science"],
    }
    "AB10006": {
      "campus": "asd",
      "subjects": ["science"],
    }
    "AB10007": {
      "campus": "cda",
      "subjects": ["science"],
    }
    "AB10008": {
      "campus": "asd",
      "subjects": ["science", "history"],
    }
    "AB10009": {
      "campus": "cda",
      "subjects": ["history"],
    }
    "AB10010": {
      "campus": "cda",
      "subjects": ["history", "maths"],
    }
  }
}

所以我想做的是通过 subjects 的学生键搜索所有做 history 的学生，然后从中创建另一个数组，包括整个学生，同时保持原始对象不变。

所以我想以这样的方式结束:

{
  "historyStudents": {
    "AB10001": {
      "campus": "cda",
      "subjects": ["history", "english"],
    }
    "AB10004": {
      "campus": "asd",
      "subjects": ["history"],
    }
    "AB10008": {
      "campus": "asd",
      "subjects": ["science", "history"],
    }
    "AB10009": {
      "campus": "cda",
      "subjects": ["history"],
    }
    "AB10010": {
      "campus": "cda",
      "subjects": ["history", "maths"],
    }
  }
}

任何见解或帮助都会非常有帮助。提前致谢!

Answer 1

您可以使用 Object.keys() 和 reduce() 来创建仅包含具有 history 主题的学生的新对象。

var data = {"students":{"AB10001":{"campus":"cda","subjects":["history","english"]},"AB10002":{"campus":"asd","subjects":["maths"]},"AB10003":{"campus":"asd","subjects":["english"]},"AB10004":{"campus":"asd","subjects":["history"]},"AB10005":{"campus":"cda","subjects":["maths","science"]},"AB10006":{"campus":"asd","subjects":["science"]},"AB10007":{"campus":"cda","subjects":["science"]},"AB10008":{"campus":"asd","subjects":["science","history"]},"AB10009":{"campus":"cda","subjects":["history"]},"AB10010":{"campus":"cda","subjects":["history","maths"]}}}

var result = {
 historyStudents: Object.keys(data.students)
  .reduce(function(r, e) {
    if(data.students[e].subjects.includes('history')) r[e] = data.students[e]
    return r;
   }, {})
 }

console.log(result)