如何基于公共属性将数组中的对象分组为数组数组

const arr = [
  { name: 'Alice', age: 20, group: 'A' },
  { name: 'Bob', age: 25, group: 'B' },
  { name: 'Charlie', age: 30, group: 'A' },
  { name: 'Dave', age: 35, group: 'B' },
  { name: 'Eve', age: 40, group: 'C' }
];

const groupedArray = arr.reduce((result, obj) => {
  const key = obj.group;
  if (!result[key]) {
    result[key] = [];
  }
  result[key].push(obj);
  return result;
}, {});

console.log(groupedArray);

{
  A: [
    { name: 'Alice', age: 20, group: 'A' },
    { name: 'Charlie', age: 30, group: 'A' }
  ],
  B: [
    { name: 'Bob', age: 25, group: 'B' },
    { name: 'Dave', age: 35, group: 'B' }
  ],
  C: [
    { name: 'Eve', age: 40, group: 'C' }
  ]
}