If we conceptually think of a folder as a list of files and subfolders, each of these operations is actually a modification of a folder.
If we conceptually think of a folder as a list of files and subfolders, each of these operations is actually a modification of a folder.
如果我们概念化的去考虑文件的目录及子目录，这些操作里面的任何一个事实上都是在修改一个目录。