如何通过 JavaScript 中的嵌套属性对数组对象进行排序

Question

我有以下对象：

const obj = {
  A: [{
    capacity: 100
  }, {
    capacity: 100
  }, {
    capacity: 100
  }],
  B: [{
    capacity: 500
  }, {
    capacity: 500
  }, {
    capacity: 500
  }],
  C: [{
    capacity: 300
  }, {
    capacity: 300
  }, {
    capacity: 300
  }]
}

我需要转换为具有相同形状但键按容量排序的对象。需要注意的是，数组（A、B、C）中每个对象的容量在同一个对象内总是相同的。所以我们可以以第一次出现为例

预期结果：

const obj = {
  A: [{
    capacity: 100
  }, {
    capacity: 100
  }, {
    capacity: 100
  }],
  C: [{
    capacity: 300
  }, {
    capacity: 300
  }, {
    capacity: 300
  }],
  B: [{
    capacity: 500
  }, {
    capacity: 500
  }, {
    capacity: 500
  }]
}

我的方法都没有奏效。一个例子：

const sortByPosition = obj => {
   const order = [], res = {};
   Object.keys(obj).forEach(key => {
      return order[obj[key][1]['capacity'] - 1] = key;
   });
   order.forEach(key => {
      res[key] = obj[key];
   });
   return res;
}

console.log(sortByPosition(obj));

这是fiddle

Answer 1

const obj = {
  A: [ { capacity: 100 }, { capacity: 100 }, { capacity: 100 } ],
  B: [ { capacity: 500 }, { capacity: 500 }, { capacity: 500 } ],
  C: [ { capacity: 300 }, { capacity: 300 }, { capacity: 300 } ]
};

console.log(Object.fromEntries(Object.entries(obj)
  .sort(([i,a],[j,b])=>a[0].capacity-b[0].capacity)));