带年龄组和查找最大日期的JavaScript分组数组

const arr = [
  { name: 'Alice', age: 25, date: '2022-01-01' },
  { name: 'Bob', age: 30, date: '2022-02-01' },
  { name: 'Charlie', age: 25, date: '2022-03-01' },
  { name: 'David', age: 30, date: '2022-04-01' },
  { name: 'Eve', age: 25, date: '2022-05-01' }
];

const groupedArray = arr.reduce((result, current) => {
  const ageGroup = result.find(group => group.age === current.age);
  if (ageGroup) {
    ageGroup.members.push(current);
  } else {
    result.push({ age: current.age, members: [current] });
  }
  return result;
}, []);

console.log(groupedArray);

[
  {
    age: 25,
    members: [
      { name: 'Alice', age: 25, date: '2022-01-01' },
      { name: 'Charlie', age: 25, date: '2022-03-01' },
      { name: 'Eve', age: 25, date: '2022-05-01' }
    ]
  },
  {
    age: 30,
    members: [
      { name: 'Bob', age: 30, date: '2022-02-01' },
      { name: 'David', age: 30, date: '2022-04-01' }
    ]
  }
]

const maxDateArray = groupedArray.map(group => {
  const maxDate = group.members.reduce((max, current) => {
    return current.date > max.date ? current : max;
  });
  return { age: group.age, maxDate };
});

console.log(maxDateArray);

[
  { age: 25, maxDate: { name: 'Eve', age: 25, date: '2022-05-01' } },
  { age: 30, maxDate: { name: 'David', age: 30, date: '2022-04-01' } }
]