减少 javascript 对象数组

Question

我有一个对象数组，我需要像对象一样返回这个集合，它们的键名需要是长度的索引。我需要过滤这个对象的值。这是数组：

const data = [
  { index: 1, value: "111" },
  { index: 2, value: "121" },
  { index: 3, value: "111" },
  { index: 5, value: "111" },
  { index: 6, value: "121" },
  { index: 7, value: "121" },
];

reduce怎么做？

我期望得到的：

{
    0: [1,3,5],
    1: [2,6,7]
}

我的错误代码：

const getGroupBy = (data) => {
  return data.reduce((acc, curr, currIndex, arr) => {
    const val = curr.value;
    const idx = curr.index;
    const fValues = arr.filter((el) => el.value === val).map(el => el.index);
    if (acc.hasOwnProperty(currIndex)) {
      acc[currIndex] = arr.filter((el) => el.value === val);
    } else {
      Object.assign(acc, { [0]: [idx] });
    }
    return acc;
  }, {});
};

Answer 1

您可以分组并将值分配给一个对象。

const
    data = [{ index: 1, value: "111" }, { index: 2, value: "121" }, { index: 3, value: "111" }, { index: 5, value: "111" }, { index: 6, value: "121" }, { index: 7, value: "121" }],
    result = Object.assign(
        {},
        Object.values(data.reduce((r, { index, value }) => ((r[value] ??= []).push(index), r), {}))
    );

console.log(result);

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

Answer 2

用值而不是 0,1 键控数组不是更有用吗？

无论如何，这里是如何减少以及如何获得 0,1 键控或键控值

const data = [
  { index: 1, value: "111" },
  { index: 2, value: "121" },
  { index: 3, value: "111" },
  { index: 5, value: "111" },
  { index: 6, value: "121" },
  { index: 7, value: "121" },
];

const indicii = data.reduce((acc,{index,value}) => {
  (acc[value] ??= []).push(index);
  return acc;
},{})
console.log({...Object.values(indicii)})
// or 
console.log(indicii);

Answer 3

我认为你必须经过这一步

1. {值：[索引]}
2. {0: 值}

这一步是为了让你的代码更简洁

  const data = [
    { index: 1, value: '111' },
    { index: 2, value: '121' },
    { index: 3, value: '111' },
    { index: 5, value: '111' },
    { index: 6, value: '121' },
    { index: 7, value: '121' },
  ];

  const getGroupBy = (data) => {
    return data.reduce((acc, curr) => {
      if (acc[curr.value]) acc[curr.value].push(curr.index);
      else acc[curr.value] = [curr.index];
      return acc;
    }, {});
  };
  console.log(getGroupBy(data));
  console.log({ ...Object.values(getGroupBy(data)) });