Why Am I Getting a NoSuchElementException When Using Scanner's nextInt()?

Scanner's nextInt() Mishap: Understanding the NoSuchElementException

When attempting to retrieve an integer using Scanner's nextInt() method, you may encounter a dreaded error: NoSuchElementException. This arises when there are no more integers available for retrieval from the input stream.

To pinpoint the culprit, we scrutinize the code snippet:

Scanner s = new Scanner(System.in);
int choice = s.nextInt(); // Error occurs here
s.close();

The nextInt() method assumes that an integer is waiting to be read, but in our case, there might not be one. To prevent this error, we can leverage the hasNextXXXX() methods provided by Scanner. These methods verify the availability of the appropriate data type, ensuring that the input is ready for retrieval.

In this specific scenario, we can rectify the issue by employing hasNextInt():

Scanner s = new Scanner(System.in);
int choice = 0;

if (s.hasNextInt()) {
    choice = s.nextInt();
}

s.close();

The hasNextInt() check ensures that an integer exists before attempting to retrieve it with nextInt(). This eliminates the possibility of the NoSuchElementException.

So, remember, when dealing with Scanner's nextInt() method, always utilize hasNextInt() to guarantee that an integer is waiting to be consumed.

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