Typescript -如何对嵌套数组进行分组

interface GroupedItem {
  key: string;
  items: any[];
}

function groupNestedArray(arr: any[], key: string): GroupedItem[] {
  const grouped: { [key: string]: any[] } = {};

  arr.forEach(item => {
    const groupKey = item[key];
    if (!grouped[groupKey]) {
      grouped[groupKey] = [];
    }
    grouped[groupKey].push(item);
  });

  return Object.keys(grouped).map(groupKey => ({
    key: groupKey,
    items: grouped[groupKey]
  }));
}

// 示例用法
const nestedArray = [
  { name: 'Alice', age: 25, group: 'A' },
  { name: 'Bob', age: 30, group: 'B' },
  { name: 'Charlie', age: 35, group: 'A' },
  { name: 'Dave', age: 40, group: 'B' },
  { name: 'Eve', age: 45, group: 'A' }
];

const groupedArray = groupNestedArray(nestedArray, 'group');
console.log(groupedArray);