es6根据某个属性将数组对象进行分组

// 数组
export function getGroupArray(list, attr) {
  const map = new Map();
  list.forEach((item, index, arr) => {
    if (!map.has(item[attr])) {
      map.set(
        item[attr],
        arr.filter(a => a[attr] == item[attr])
      );
    }
  });
  return Array.from(map).map(item => [...item[1]]);
}
// 对象
export function getGroupObject(list, attr) {
  const map = new Map();
  list.forEach((item, index, arr) => {
    if (!map.has(item[attr])) {
      map.set(
        item[attr],
        arr.filter(a => a[attr] == item[attr])
      );
    }
  });
  return Object.fromEntries(Array.from(map).map(item => [item[0], item[1]]));
}