小编Bai*_*iao的帖子

var a = [
  {id: 1, name: "phone"},
  {id: 2,  name: "nick"}
];

var b = [
  {id: 7, parentId: 1, name: "phone_item1"},
  {id: 8, parentId: 2, name: "phone_item2"},
  {id: 9, parentId: 1, name: "nick_item1"},
  {id: 10, parentId: 2, name: "nick_item2"}
];

//You want to filter by A array id
const filterIds = a.map(({ id }) => id);

//My attempt
const c = Object.values(b.reduce((r, c) => {
  r[c.parentId] = r[c.parentId] || [];
  r[c.parentId].push(c);
  return r; …