How to Prevent Infinite Loops When Handling Invalid Integer Input with Java's Scanner?

try/catch with InputMismatchException Looping Issue

When attempting to handle user input with a try/catch block and an InputMismatchException, you may encounter an infinite loop if the input is not an integer. To resolve this, ensure you call next() to advance the Scanner past the invalid input.

catch (Exception e) {
    System.out.println("Error!");
    input.next(); // Advance past invalid input
}

Additionally, it's advisable to use hasNextInt() to check for valid integer input before reading it.

while (bError) {
    if (scanner.hasNextInt())
        n1 = scanner.nextInt();
    else {
        scanner.next(); // Advance past invalid input
        continue;
    }
    // Repeat for n2
}

This approach ensures that the Scanner skips non-integer input and only proceeds with valid values, eliminating the need for exception handling.

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