访问嵌套对象数组的所有单个值？

问题描述

我正在尝试访问每个项目的每个列表对象的单独计数值，以在数组中使用它们。我尝试了各种地图方法，但始终返回未定义状态。我需要一种动态的方法来收集这些计数，以便在添加更多列表，项目，位置和计数时，它会更新。

数据：

const data = [
  {
    name: "List1",items: [
      {
        name: "Item1",locations: [
          { position: "a",count: 20 },{ position: "b",count: 30 },],},{
        name: "Item2",locations: [
          { position: "c",count: 40 },{ position: "d",count: 50 },{
    name: "List2",items: [
      {
        name: "Item3",locations: [
          { position: "e",count: 60 },{ position: "f",count: 70 },{
        name: "Item4",locations: [
          { position: "g",count: 80 },{ position: "h",count: 90 },];

所需结果：

const onlyCounts = [20,30,40,50,60,70,80,90];

任何提示或信息将不胜感激，谢谢！

解决方法

如果由于不确定嵌套对象的形状/键/深度而需要通用解决方案，那么只要您的数据没有任何周期，这是一种递归解决方案。

const getCounts = (value) =>
  value.flatMap((el) =>
    Object.entries(el).flatMap(([key,value]) => {
      if (key === "count") return [value];
      if (Array.isArray(value)) return getCounts(value);
      return [];
    })
  );

const data = [
  {
    name: "List1",items: [
      {
        name: "Item1",locations: [
          { position: "a",count: 20 },{ position: "b",count: 30 }
        ]
      },{
        name: "Item2",locations: [
          { position: "c",count: 40 },{ position: "d",count: 50 }
        ]
      }
    ]
  },{
    name: "List2",items: [
      {
        name: "Item3",locations: [
          { position: "e",count: 60 },{ position: "f",count: 70 }
        ]
      },{
        name: "Item4",locations: [
          { position: "g",count: 80 },{ position: "h",count: 90 }
        ]
      }
    ]
  }
];

const getCounts = (value) =>
  value.flatMap((el) =>
    Object.entries(el).flatMap(([key,value]) => {
      if (key === "count") return [value];
      if (Array.isArray(value)) return getCounts(value);
      return [];
    })
  );

console.log(getCounts(data))

真正广义的解决方案

const getFieldArray = (value,field) =>
  value.flatMap((el) =>
    Object.entries(el).flatMap(([key,value]) => {
      if (key === field) return [value];
      if (Array.isArray(value)) return getFieldArray(value,field);
      return [];
    })
  );

console.log(getFieldArray(data,'count'));