Answer 1

Just like memory, the file is a resource that your program is using. when you don't need it anymore you close the connection.
Also at writing in a file, if you have data in a buffer and you don't use the close method then you could pottentialy lose data.

Here is a similar question to yours that i found in the forum. Please use the search bar in the future to check if your question was asked before.

https://www.sololearn.com/Discuss/2236399/is-it-really-necessary-to-use-scan-close-after-usage-of-scanner-in-every-program