如何在Javascript中分组并在不存在空对象时添加空对象

const data = [
  { name: 'Alice', group: 'A' },
  { name: 'Bob', group: 'B' },
  { name: 'Charlie', group: 'A' },
  { name: 'Dave', group: 'C' },
  { name: 'Eve', group: 'B' }
];

const groupedData = data.reduce((result, obj) => {
  const group = obj.group;
  
  // 如果result中不存在该组，则添加一个空对象
  if (!result[group]) {
    result[group] = [];
  }
  
  result[group].push(obj);
  
  return result;
}, {});

{
  A: [
    { name: 'Alice', group: 'A' },
    { name: 'Charlie', group: 'A' }
  ],
  B: [
    { name: 'Bob', group: 'B' },
    { name: 'Eve', group: 'B' }
  ],
  C: [
    { name: 'Dave', group: 'C' }
  ]
}