Why Am I Getting a 'NoSuchElementException' When Using Java's Scanner Class?

Troubleshooting "NoSuchElementException" in Java.Util.Scanner

The "NoSuchElementException" error in Java is typically caused by an attempt to read from a closed or empty input source using the Scanner class. In your case, this exception is occurring when you try to read the second integer from the user (line 17 in your code).

To debug this issue, let's examine the Scanner class in detail:

Scanner Class

The Scanner class allows you to read text data from a source, such as System.in (the console). Its methods allow you to extract various data types, including integers (nextInt()), from the source.

In your code, you create a Scanner object called "input" to read input from the console. You then attempt to read two integer values into variables number1 and number2.

Error Analysis

The "NoSuchElementException" error suggests that the Scanner object is expecting to find an integer on the next line of input but cannot find one. This can occur for several reasons:

• No Integer Input: Make sure that you have actually entered two integers on separate lines in the console.
• Incorrect Input Type: Double-check that the input you are providing is of type int.
• Scanner Closed: Ensure that the Scanner is not closed before attempting to read input.

Proposed Solution

To resolve this issue, consider adding a check to verify that the Scanner has another integer to read before attempting to extract it:

if (input.hasNextInt()) {
  number2 = input.nextInt(); 
} else {
  // Handle the case where no integer is found
  // (e.g., display an error message or set number2 to a default value)
}

By incorporating this check, you can determine if there is another integer available before trying to read it. If there is none, you can take appropriate action, such as displaying an error message or setting number2 to a default value.

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