[Kotlin] list.groupBy
data class Notice(val no: Long, val name: String) data class File(val no: Long, val name: String, val noticeNo: Long) data class NoticeWithFiles(val no: Long, val name: String, val files: List) val notices = listOf(Notice(1L, "1"), Notice(2L, "2"), Notice(3L, "3")) val files = listOf(File(1L, "1", noticeNo = 1), File(2L, "2", noticeNo = 1), File(3L, "3", noticeNo = 1), File(4L, "4", noticeNo = 2..
2019. 10. 17.
