过滤嵌套数组并返回与键值匹配的数组答案

【问题标题】：Filtering a nested array and return the array which matches the value for the key过滤嵌套数组并返回与键值匹配的数组
【发布时间】：2021-11-21 05:47:03
【问题描述】：

我正在尝试根据 id 过滤包含对象数组的数组。我可以过滤它们，但需要稍微清理一下输出，因为它还返回一个空数组，因为条件与该数组不匹配。

我该如何解决？

const resKey = 'ABC';
const data = [
  [{
    "user": {
      "firstName": "John",
      "lastName": "Smith",
    },
    "id": "ABC"
  }],
  [{
    "user": {
      "firstName": "John",
      "lastName": "Smith",
    },
    "id": "DEF"
  }]
];

const result = data.map(eachArr => eachArr.filter(eachObj => eachObj.id === resKey));
console.log(result);

预期输出：

[
  [
    {
      user: {
        firstName: "John",
        lastName: "Smith",
      },
      id: "ABC",
    },
  ],
]

实际输出：

[
  [
    {
      user: {
        firstName: "John",
        lastName: "Smith",
      },
      id: "ABC",
    },
  ],
  [],
]

【问题讨论】：

标签： javascript arrays object filter nested

【解决方案1】：

您可以再次使用filter 过滤掉不包含元素的空数组（length 是0）。

.filter((arr) => arr.length);

const resKey = "ABC";
const data = [
  [
    {
      user: {
        firstName: "John",
        lastName: "Smith",
      },
      id: "ABC",
    },
  ],
  [
    {
      user: {
        firstName: "John",
        lastName: "Smith",
      },
      id: "DEF",
    },
  ],
];

const result = data
  .map((eachArr) => eachArr.filter((eachObj) => eachObj.id === resKey))
  .filter((arr) => arr.length);
  
console.log(result);

【讨论】：