按组名和子项对对象数组进行分组答案

【问题标题】：group an array of object by group name and children按组名和子项对对象数组进行分组
【发布时间】：2021-04-28 22:54:51
【问题描述】：

我有一个对象数组。我需要按 groups 和 children 对这个数组进行分组。我尝试创建一个新数组，其中组名作为键，值作为按组分组的排序数组，但没有给我例外格式。我该怎么做？

以下是我的数据格式：

var data1 = [{
    "Name": "Apparel",
    "categoryId": 2742,
    "categoryName": "Men",
  },
  {
    "Name": "Fragrances",
    "categoryId": 2746,
    "categoryName": "Men",
  },
  {
    "Name": "Apparel",
    "categoryId": 2742,
    "categoryName": "Women",
  },
  {
    "Name": "Fragrances",
    "categoryId": 2746,
    "categoryName": "Women",
  }
];

预期输出是：

var data2 = [{
    "categoryName": "Men",
    "children": [{
        "Name": "Apparel",
        "categoryId": 2742
      },
      {
        "Name": "Fragrances",
        "categoryId": 2746
      }
    ]
  },
  {
    "categoryName": "Women",
    "children": [{
        "Name": "Apparel",
        "categoryId": 2742
      },
      {
        "Name": "Fragrances",
        "categoryId": 2746
      }
    ]
  }
]

我使用了这个函数，但输出不如预期，但非常接近解决方案

function groupAndSort(array, groupField, sortField) {
  var groups = {}; // This object will end being keyed by groups, and elements will be arrays of the rows within the given array, which have been sorted by the sortField
  // Put all the rows into groups
  for (var i = 0; i < array.length; i++) {
    var row = array[i];
    var groupValue = row[groupField];
    groups[groupValue] = groups[groupValue] || [];
    groups[groupValue].push(row);
  }
  // Sort each group
  for (var groupValue in groups) {
    groups[groupValue] = groups[groupValue].sort(function(a, b) {
      return a[sortField] - b[sortField];
    });
  }
  // Return the results
  return groups;
}

groupAndSort(data1, "categoryName", "position"))

这是该代码的输出：

{
  Men: [{
  categoryId: 2742,
  categoryName: "Men",
  Name: "Apparel"
}, {
  categoryId: 2746,
  categoryName: "Men",
  Name: "Fragrances"
}],
  Women: [{
  categoryId: 2742,
  categoryName: "Women",
  Name: "Apparel"
}, {
  categoryId: 2746,
  categoryName: "Women",
  Name: "Fragrances"
}]
}

我非常接近解决方案，我只需要一些帮助即可按预期完成，非常感谢您的帮助

【问题讨论】：

标签： javascript arrays sorting object grouping

【解决方案1】：

从您离开的地方开始，您所要做的就是遍历对象并将键和关联的数组推送到新的最终数组。

const data = {
  Men: [{
  categoryId: 2742,
  categoryName: "Men",
  Name: "Apparel"
}, {
  categoryId: 2746,
  categoryName: "Men",
  Name: "Fragrances"
}],
  Women: [{
  categoryId: 2742,
  categoryName: "Women",
  Name: "Apparel"
}, {
  categoryId: 2746,
  categoryName: "Women",
  Name: "Fragrances"
}]
}

const final = [];

for (const key in data) {
  final.push({
    categoryName: key,
    children: data[key]
  })
}

console.log(final);

【讨论】：

【解决方案2】：

您需要分组对象的 Object.values()

const group  = {}; 

data1.forEach(({categoryName, ...rest})=>{
    group[categoryName] = group[categoryName] || {categoryName, children:[]};
    group[categoryName].children.push(rest)
});

const res = Object.values(group)

console.log(res)

<script>
var data1 = [ 
          {
           "Name": "Apparel",
           "categoryId": 2742,
        "categoryName": "Men",
          },
          {
           "Name": "Fragrances",
           "categoryId": 2746,
             "categoryName": "Men",
          },
           {
           "Name": "Apparel",
           "categoryId": 2742,
             "categoryName": "Women",
          },
          {
           "Name": "Fragrances",
           "categoryId": 2746,
          "categoryName": "Women",
          }
         ];
</script>

【讨论】：

【解决方案3】：

你的groups对象的key是categoryName，value是children数组，所以一个简单的映射：

  // Return the results
  // return groups;
  return Object.entries(groups).map(([categoryName, children]) => ({categoryName, children}));

【讨论】：

按预期工作，这是正确的解决方案，谢谢