javascript - 比较两个数组的 id | Reactjs

Question

我有两个数据数组。一个数组(allGroups)包含用户关注和未关注的所有组的数据，另一个数组(followingGroups)仅包含用户关注的组的列表。现在，我想将 allGroups 数组数据 id 与 followGroups 数组数据 id 进行比较，我需要找到它们，它们都具有相同的 id。我需要列出所有组，如果一个组具有相同的 id，我需要显示，用户正在 View 中关注该组，否则请关注。请让我知道，我怎样才能实现这一目标。请检查我下面的数组数据。

//allGroups array

allGroups = [
{"id": 0, "name": "books", "purpose": "to read"},
{"id": 1, "name": "dress", "purpose": "to wear"},
{"id": 2, "name": "shoe", "purpose": "to walk"},
{"id": 3, "name": "food", "purpose": "to eat"},
{"id": 4, "name": "nature", "purpose": "to view"}
]

//followingGroups array

followingGroups = [
{"following":{"id": 2, "name": "shoe", "purpose": "to walk"}},
{"following":{"id": 3, "name": "food", "purpose": "to eat"}},
{"following":{"id": 4, "name": "nature", "purpose": "to view"}}
]

Answer 1

很简单，只需选择您要比较的字段即可，您还应该阅读此文档 array loop

const allGroups = [
  {"id": 0, "name": "books", "purpose": "to read"},
  {"id": 1, "name": "dress", "purpose": "to wear"},
];

const userGroups = [
  {"following":{"id": 0, "name": "shoe", "purpose": "to walk"}},
  {"following":{"id": 3, "name": "food", "purpose": "to eat"}},
  {"following":{"id": 4, "name": "nature", "purpose": "to view"}}
];

// Collect ids of allGroups
const ids = allGroups.map(group => group.id);

const sameGroup = userGroups.map(group => {
  const { following } = group;

  if (ids.includes(following.id)) {
    console.log(JSON.stringify(group))
    return group; // return group with id: 0
  }
});