Javascript:对象数组的哈希(使用扑克牌示例)

Question

我想了解如何正确创建对象数组的哈希值。

在此示例中，我有一副牌(我省略了一些牌以缩短示例):

var deckOfCards = [
  {color: "red", coat: "hearts", id: "Ace", faceValue: "A"},
  {color: "black", coat: "clubs", id: "Ace", faceValue: "A"},
  {color: "red", coat: "diamonds", id: "Ace", faceValue: "A"},
  {color: "black", coat: "spades", id: "Ace", faceValue: "A"},
  {color: "red", coat: "hearts", id: "Two", faceValue: "2"},
  {color: "black", coat: "clubs", id: "Two", faceValue: "2"},
  {color: "red", coat: "diamonds", id: "Two", faceValue: "2"},
  {color: "black", coat: "spades", id: "Two", faceValue: "2"},
  {color: "red", coat: "hearts", id: "Three", faceValue: "3"},
  {color: "black", coat: "clubs", id: "Three", faceValue: "3"},
  {color: "red", coat: "diamonds", id: "Three", faceValue: "3"},
  {color: "black", coat: "spades", id: "Three", faceValue: "3"},
  {color: "red", coat: "hearts", id: "Jack", faceValue: "J"},
  {color: "black", coat: "clubs", id: "Jack", faceValue: "J"},
  {color: "red", coat: "diamonds", id: "Jack", faceValue: "J"},
  {color: "black", coat: "spades", id: "Jack", faceValue: "J"},
  {color: "red", coat: "hearts", id: "Queen", faceValue: "Q"},
  {color: "black", coat: "clubs", id: "Queen", faceValue: "Q"},
  {color: "red", coat: "diamonds", id: "Queen", faceValue: "Q"},
  {color: "black", coat: "spades", id: "Queen", faceValue: "Q"},
  {color: "red", coat: "hearts", id: "King", faceValue: "K"},
  {color: "black", coat: "clubs", id: "King", faceValue: "K"},
  {color: "red", coat: "diamonds", id: "King", faceValue: "K"},
  {color: "black", coat: "spades", id: "King", faceValue: "K"}
];

我现在定义了要用于卡片分组的不同哈希...

var hashOfCardsByColor = [];
var hashOfCardsByCoat = [];
var hashOfCardsById = [];
var hashOfCardsByFaceValue = [];

当我遍历这副牌时，我想:

1. 在尝试将卡放入哈希之前检查哈希 key 是否存在，如果 key 不存在，则创建它。
2. 将卡片放入可以通过该键访问的卡片数组中。

我的代码...

  deckOfCards.forEach(function(d, i){
    // Handle coats...
    if (d.coat == "hearts") {
      // 1. If "hearts" key doesn't exist, create it and push card onto Array that it points to
      // 2. If "hearts" key does exist, just push card onto Array that it points to
    }
    else if (d.coat == "clubs") {
      // 1. If "clubs" key doesn't exist, create it and push card onto Array that it points to
      // 2. If "clubs" key does exist, just push card onto Array that it points to
    }
    else if (d.coat == "diamonds") {
      // 1. If "diamonds" key doesn't exist, create it and push card onto Array that it points to
      // 2. If "diamonds" key does exist, just push card onto Array that it points to
    }
    else (d.coat == "spades") {
      // 1. If "spades" key doesn't exist, create it and push card onto Array that it points to
      // 2. If "spades" key does exist, just push card onto Array that it points to
    }      
  });

我正在努力解决上面每个段正文中步骤 1 和 2 的语法和代码，感谢您提供的任何帮助。

此外，“数组哈希”是上述的正确描述还是“ HashMap ”？

Answer 1

好吧，兄弟，简单点。

  var hash = {};
    deckOfCards.forEach(function (e) {
        hash[e.coat] = hash[e.coat] || [];
        hash[e.coat].push(e);
    });

您的结果将如下所示

对象{红心:数组[6]，梅花:数组[6]，方 block :数组[6]，黑桃:数组[6]}

只需复制粘贴即可在控制台中查看。如果这个答案解决了您的问题，必须投票并检查是否确定。