如何在Json中按关键数据分组

const data = [
  { name: 'Alice', age: 25, group: 'A' },
  { name: 'Bob', age: 30, group: 'B' },
  { name: 'Charlie', age: 25, group: 'A' },
  { name: 'David', age: 30, group: 'B' }
];

function groupBy(data, key) {
  return data.reduce((result, item) => {
    (result[item[key]] = result[item[key]] || []).push(item);
    return result;
  }, {});
}

const groupedData = groupBy(data, 'age');
console.log(groupedData);

function cleanData(data) {
  return data.filter(item => item.age !== undefined);
}

const cleanedData = cleanData(data);
const groupedData = groupBy(cleanedData, 'age');

const _ = require('lodash');

const groupedData = _.groupBy(data, 'age');