Close the given resource ID (rid) which has been previously opened, such as via opening or creating a file. Closing a file when you are finished with it is important to avoid leaking resources.

const file = await Deno.open("my_file.txt");
// do work with "file" object
Deno.close(file.rid);

It is recommended to define the variable with the using keyword so the runtime will automatically close the resource when it goes out of scope. Doing so negates the need to manually close the resource.

using file = await Deno.open("my_file.txt");
// do work with "file" object