JS List 分組函數

  groupArr(list: Array<any>, field: string) {
    var fieldList: Set<string> = new Set(),
      att = [];
    list.map(e => {
      fieldList.add(e[field]);
    });
    for (let item of fieldList) {
      var arr = list.filter(e => {
        return e[field] == item;
      });
      att.push({
        GroupName: item,
        list: arr
      });
    }
    console.log(att);
    return att;
  }