按键将对象分组为二维数组

Question

我有一个对象数组。这些对象都有一个叫做time的属性。如果它们的time相同，我想将这些对象分组到同一个数组中。

{ "00:00" :
   [{"id":1, time: "00:05",
    {"id":1, time: "00:15",
    {"id":1, time: "00:20",
    {"id":2, time: "00:05",
    {"id":3, time: "00:05",
    {"id":4, time: "00:35 }]
}

我希望将上述数据格式化为：

{ "00:00" :[
    [{"id":1, time: "00:05"}, {"id":2, time: "00:05"}, {"id":3, time: "00:05"}],
    [{"id":1, time: "00:15" }],
    [{"id":1, time: "00:20" }],      
    [{"id":4, time: "00:35" }]]
}

有什么建议可以帮助我完成这个任务吗？

- Ekoar

---

有很多像“00:00”这样的属性吗，还是只有一个？ - Eddie

可能会有“01:00”，“02:00”等。 - Ekoar

Answer 1

你可以使用reduce来总结你的对象，也可以使用Object.values将对象转换为数组。

let obj={"00:00" :[{"id":1,time:"00:05"},{"id":1,time:"00:15"},{"id":1,time:"00:20"},{"id":2,time:"00:05"},{"id":3,time:"00:05"},{"id":4,time:"00:35"}],"02:00" :[{"id":1,time:"00:05"},{"id":1,time:"00:15"},{"id":1,time:"00:20"},{"id":2,time:"00:05"},{"id":3,time:"00:05"},{"id":4,time:"00:35"}]}

var result = Object.entries(obj).reduce((c, v) => {
  c[v[0]] = Object.values(v[1].reduce((a, o) => {
    a[o.time] = a[o.time] || [];
    a[o.time].push(o);
    return a;
  }, {}));
  return c;
}, {});


console.log(result);

- Eddie

Answer 2

使用 .reduce 将所有匹配的对象放入对象内部的一个由时间索引的数组中，然后从该对象中提取值：

const input = { "00:00" :
   [{"id":1, time: "00:05"},
    {"id":1, time: "00:15"},
    {"id":1, time: "00:20"},
    {"id":2, time: "00:05"},
    {"id":3, time: "00:05"},
    {"id":4, time: "00:35" }]
};
const outputObj = input['00:00'].reduce((accum, { id, time }) => {
  if (!accum[time]) accum[time] = [];
  accum[time].push({ id, time });
  return accum;
}, {});
const outputArr = Object.values(outputObj);
console.log(outputArr);

你可以将其扩展到适用于 input 数组的多个属性：

const input = { "00:00" :
   [{"id":1, time: "00:05"},
    {"id":1, time: "00:15"},
    {"id":1, time: "00:20"},
    {"id":2, time: "00:05"},
    {"id":3, time: "00:05"},
    {"id":4, time: "00:35" }],
    "01:00" :
   [{"id":1, time: "01:05"},
    {"id":1, time: "01:15"},
    {"id":1, time: "01:20"},
    {"id":2, time: "01:05"},
    {"id":3, time: "01:05"},
    {"id":4, time: "01:35" }],
};
function transformInputArrToGroupedArr(inputArr) {
  const outputObj = inputArr.reduce((accum, { id, time }) => {
    if (!accum[time]) accum[time] = [];
    accum[time].push({ id, time });
    return accum;
  }, {});
  return Object.values(outputObj);
}
const transformedInput = Object.entries(input).reduce((accum, [ key, arr ]) => {
  accum[key] = transformInputArrToGroupedArr(arr);
  return accum;
}, {});
console.log(transformedInput);

- CertainPerformance

Answer 3

您可以尝试使用数组的reduce()方法，像以下这样：

var obj = { "00:00" :
   [{"id":1, time: "00:05"},
    {"id":1, time: "00:15"},
    {"id":1, time: "00:20"},
    {"id":2, time: "00:05"},
    {"id":3, time: "00:05"},
    {"id":4, time: "00:35" }]
}

var res = obj['00:00'].reduce(function(a, c){
  a[c.time] = a[c.time] || [];
  a[c.time].push(c);
  return a;
}, {});

console.log(res);

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- Mamun