Javascript->添加具有相同名稱的嵌套對象的值

Question

我正在嘗試計算每個問題每個玩家的總得分。

對於每個問題，我都采用以下格式檢索數據。

[
  {
    "_id":"5ab24e5e49e0f20a06d73ab7",
    "player":"Kareltje",
    "answers":
    [
      {
        "_id":"5ab227cf07818240934b11a5",
        "player":"Peter",
        "comment":"",
        "points":7,
        "__v":0
      },
      {
        "_id":"5ab24bf3b8494c76fd0bb31a",
        "player":"André",
        "comment":"",
        "points":6,
        "__v":0
      },
      {
        "_id":"5ab24bf7b8494c76fd0bb31b",
        "player":"Maikel",
        "comment":"",
        "points":5,
        "__v":0
      },
      {
        "_id":"5ab24bfab8494c76fd0bb31c",
        "player":"Iebele",
        "comment":"",
        "points":4,
        "__v":0
      },
      {
        "_id":"5ab24bfeb8494c76fd0bb31d",
        "player":"Bettina",
        "comment":"",
        "points":3,
        "__v":0
      },
      {
        "_id":"5ab24c01b8494c76fd0bb31e",
        "player":"Shirley",
        "comment":"",
        "points":2,
        "__v":0
      },
      {
        "_id":"5ab24c04b8494c76fd0bb31f",
        "player":"Suzanne",
        "comment":"",
        "points":1,
        "__v":0
      }
    ],
    "question":1,"__v":0
  },
  {
    "_id":"5ab24fa21e7caa1132720e7a",
    "player":"Maikel",
    "answers":
    [
      {
        "_id":"5ab24c04b8494c76fd0bb31f",
        "player":"Suzanne",
        "comment":"",
        "points":7,
        "__v":0
      },
      {
        "_id":"5ab24bfab8494c76fd0bb31c",
        "player":"Iebele",
        "comment":"",
        "points":6,
        "__v":0
      },
      {
        "_id":"5ab24bf3b8494c76fd0bb31a",
        "player":"André",
        "comment":"",
        "points":5,
        "__v":0
      },
      {
        "_id":"5ab24c01b8494c76fd0bb31e",
        "player":"Shirley",
        "comment":"",
        "points":4,
        "__v":0
      },
      {
        "_id":"5ab24bf7b8494c76fd0bb31b",
        "player":"Maikel",
        "comment":"",
        "points":3,
        "__v":0
      },
      {
        "_id":"5ab24bfeb8494c76fd0bb31d",
        "player":"Bettina",
        "comment":"",
        "points":2,
        "__v":0
      },
      {
        "_id":"5ab227cf07818240934b11a5",
        "player":"Peter",
        "comment":"",
        "points":1,
        "__v":0
      }
    ],
    "question":1,"__v":0
  }
]

我希望基於此數據為每個玩家獲得總分，但是我似乎找不到代碼來累加每個玩家的積分。

結果是：彼得：14安德烈：12邁克爾：10伊比勒：8

關於如何實現這一目標的任何想法？

我試圖用下面的代碼得到要點：

var { data, players } = this.state;
var ArrLength = data.length;
console.log(data);
var j;
var x;
for (j = 0; j < ArrLength; j++) {
  let answer = data[j].answers;
  for (x = 0; x < answer.length; x++) {
    console.log(answer[`${x}`].points);
  }
}

這至少告訴我console.log中每個玩家的得分。 但是現在添加它們以獲得最終結果是我似乎無法弄清楚的事情。

Answer 1

您可以使用Map進行計數，並使用數據構建一個數組。

 var data = [{ answers: [{ _id: "5ab227cf07818240934b11a5", player: "Peter", comment: "", points: 7, __v: 0 }, { _id: "5ab24bf3b8494c76fd0bb31a", player: "André", comment: "", points: 6, __v: 0 }, { _id: "5ab24bf7b8494c76fd0bb31b", player: "Maikel", comment: "", points: 5, __v: 0 }, { _id: "5ab24bfab8494c76fd0bb31c", player: "Iebele", comment: "", points: 4, __v: 0 }], player: "Pieter", question: 1, __v: 0, _id: "5ab24e5e49e0f20a06d73ab7" }, { answers: [{ _id: "5ab227cf07818240935b11a5", player: "Peter", comment: "", points: 7, __v: 0 }, { _id: "5ab24bf3b8494c76fd8bb31a", player: "André", comment: "", points: 6, __v: 0 }, { _id: "5ab24bf7b8494c76fd2bb31b", player: "Maikel", comment: "", points: 5, __v: 0 }, { _id: "5ab24bfab8494c76fd9bb31c", player: "Iebele", comment: "", points: 4, __v: 0 }], player: "Kareltje", question: 1, __v: 0, _id: "5ab24e5e49e0f20b86d73ab7" }], score = Array.from( data.reduce((m, { answers }) => answers.reduce((n, { player, points }) => n.set(player, (n.get(player) || 0) + points), m), new Map), ([player, score]) => ({ player, score }) ); console.log(score); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 2

您可以使用此替代方法。

使用函數reduce和forEach函數。

• reduce積累。
• forEach遍歷答案。

 var data = [{ answers: [ { _id: "5ab227cf07818240934b11a5", player: "Peter", comment: "", points: 7, __v: 0 } , { _id: "5ab24bf3b8494c76fd0bb31a", player: "André", comment: "", points: 6, __v: 0 } , { _id: "5ab24bf7b8494c76fd0bb31b", player: "Maikel", comment: "", points: 5, __v: 0 } , { _id: "5ab24bfab8494c76fd0bb31c", player: "Iebele", comment: "", points: 4, __v: 0 } ], player: "Pieter", question: 1, __v: 0, _id: "5ab24e5e49e0f20a06d73ab7"},{ answers: [ { _id: "5ab227cf07818240935b11a5", player: "Peter", comment: "", points: 7, __v: 0 }, { _id: "5ab24bf3b8494c76fd8bb31a", player: "André", comment: "", points: 6, __v: 0 } , { _id: "5ab24bf7b8494c76fd2bb31b", player: "Maikel", comment: "", points: 5, __v: 0 } ,{ _id: "5ab24bfab8494c76fd9bb31c", player: "Iebele", comment: "", points: 4, __v: 0 } ], player: "Kareltje", question: 1, __v: 0, _id: "5ab24e5e49e0f20b86d73ab7"}]; var result = data.reduce((a, {answers}) => { answers.forEach(({player, points}) => a[player] = (a[player] || 0) + points); return a; }, {}); console.log(result); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 3

您只需使用外部陣列即可。 它基本上對points每個元素使用相同的鍵，並驗證鍵是否已設置（如果未設置，則設置為零），並對與相同鍵相關的點求和。

PS： _id在json中不是唯一的。

由於您提供的JSON無效，因此我使用以下代碼：

var arr = [
    {
        answers: [{
                _id: "5ab227cf07818240934b11a5", 
                player: "Peter", 
                comment: "", 
                points: 7, 
                __v: 0
            }, {
                _id: "5ab24bf3b8494c76fd0bb31a", 
                player: "André", 
                comment: "", 
                points: 6, 
                __v: 0
            }, {
                _id: "5ab24bf7b8494c76fd0bb31b", 
                player: "Maikel", 
                comment: "", 
                points: 5, 
                __v: 0
            }, {
                _id: "5ab24bfab8494c76fd0bb31c", 
                player: "Iebele", 
                comment: "", 
                points: 4, 
                __v: 0
            }
        ],
        player: "Pieter",
        question: 1,
        __v: 0,
        _id: "5ab24e5e49e0f20a06d73ab7"
    }, {
        answers: [{
                _id: "5ab227cf07818240935b11a5", 
                player: "Peter", 
                comment: "", 
                points: 7, 
                __v: 0
            }, {
                _id: "5ab24bf3b8494c76fd8bb31a", 
                player: "André", 
                comment: "", 
                points: 6, 
                __v: 0
            }, {
                _id: "5ab24bf7b8494c76fd2bb31b", 
                player: "Maikel", 
                comment: "", 
                points: 5, 
                __v: 0
            }, {
                _id: "5ab24bfab8494c76fd9bb31c", 
                player: "Iebele", 
                comment: "", 
                points: 4, 
                __v: 0
            }
        ],
        player: "Kareltje",
        question: 1,
        __v: 0,
        _id: "5ab24e5e49e0f20b86d73ab7"
    }
]

var points = {};
for (var i in arr) {
    for (var j in arr[i].answers) {
        if (!points[arr[i].answers[j].player]) {
            points[arr[i].answers[j].player] = 0;
        }
        points[arr[i].answers[j].player] += arr[i].answers[j].points;
    }
}

Answer 4

您可以使用.reduce遍歷數組並匯總所有分數：

 const data = [{"answers":[{"_id":"5ab227cf07818240934b11a5","player":"Peter","comment":"","points":7,"__v":0},{"_id":"5ab24bf3b8494c76fd0bb31a","player":"André","comment":"","points":6,"__v":0},{"_id":"5ab24bf7b8494c76fd0bb31b","player":"Maikel","comment":"","points":5,"__v":0},{"_id":"5ab24bfab8494c76fd0bb31c","player":"Iebele","comment":"","points":4,"__v":0}],"player":"Pieter","question":1,"__v":0,"_id":"5ab24e5e49e0f20a06d73ab7"},{"answers":[{"_id":"5ab227cf07818240935b11a5","player":"Peter","comment":"","points":7,"__v":0},{"_id":"5ab24bf3b8494c76fd8bb31a","player":"André","comment":"","points":6,"__v":0},{"_id":"5ab24bf7b8494c76fd2bb31b","player":"Maikel","comment":"","points":5,"__v":0},{"_id":"5ab24bfab8494c76fd9bb31c","player":"Iebele","comment":"","points":4,"__v":0}],"player":"Kareltje","question":1,"__v":0,"_id":"5ab24e5e49e0f20b86d73ab7"}]; const scores = data.reduce( (scores, d) => { d.answers.forEach( answer => { scores[answer.player] = (scores[answer.player]||0) + answer.points; }); return scores; }, {}); console.log(scores);