That’s because the Scanner.nextInt method does not read the newline character in your input created by hitting “Enter,” and so the call to Scanner.nextLine returns after reading that newline.

You will encounter the similar behaviour when you use Scanner.nextLine after Scanner.next() or any Scanner.nextFoo method (except nextLine itself).

Workaround:

  • Either put a Scanner.nextLine call after each Scanner.nextInt or Scanner.nextFoo to consume rest of that line including newline

    int option = input.nextInt();
    input.nextLine();  // Consume newline left-over
    String str1 = input.nextLine();
    
  • Or, even better, read the input through Scanner.nextLine and convert your input to the proper format you need. For example, you may convert to an integer using Integer.parseInt(String) method.

    int option = 0;
    try {
        option = Integer.parseInt(input.nextLine());
    } catch (NumberFormatException e) {
        e.printStackTrace();
    }
    String str1 = input.nextLine();