How Can I Close a Scanner Linked to System.in Without Affecting System.in?

Closing a Scanner Linked to System.in Without Affecting System.in

In programming, it's considered good practice to close resources when finished using them, including scanners linked to the standard input stream (System.in). However, closing the scanner can inadvertently close System.in, leading to complications.

Is it Possible to Close the Scanner Without Closing System.in?

Yes, there is a way to close the scanner without affecting System.in. However, it's not a recommended approach.

Recommended Approach: Keep the Scanner Open

The simplest and recommended solution is to refrain from closing the scanner if you don't want to close System.in. Ideally, create a single scanner instance and use it for the duration of your program.

Why Closing Scanner Can Affect System.in

When you close a scanner, it invokes the close() method on its underlying input stream, which in this case is System.in. Closing the input stream prevents further input from being read from the standard input.

Potential Consequences of Closing Scanner

Depending on your program's design, closing the scanner can have various consequences:

• If your program expects further input from System.in, it may fail or behave unexpectedly.
• Interactive programs that rely on user interaction may freeze or become unusable.
• Other processes in the system may be impacted, if they rely on System.in for input.

Conclusion

While there is a technical solution to close the scanner without closing System.in, it's not generally advised. The recommended approach is to keep the scanner open and close it when the program exits, especially when System.in is used for ongoing input.

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