Java 为什么我需要输入我的选择两次？

有人能帮我理解为什么程序要求我在继续之前输入两次选择吗

public static void main(String[] args) {
    String quit = "quit";
    String input =  "input";
    String print = "print";


    @SuppressWarnings("resource")
    Scanner scan = new Scanner(System.in);
    System.out.println("please enter a command : \n      1) Quit \n      2) Input \n      3) Print \n");

    String initialSelection = scan.next();
    boolean stringInput = scan.hasNext();
    boolean intInput = scan.hasNextInt();
    boolean boolinput = scan.hasNextBoolean();

    if(initialSelection.equalsIgnoreCase(quit)) {
        System.out.println("The program has quit.");
        System.exit(0);
    }else if(initialSelection.equalsIgnoreCase(print)){
        [constructor]

        do {
            System.out.println("\nplease enter a command : \n      1) Quit \n      2) Input \n      3) Print \n");
            initialSelection = scan.nextLine();

                if (initialSelection.equalsIgnoreCase(print)) {
                        new BonusArrayList();
                } else if(initialSelection.equalsIgnoreCase(quit)) {
                            System.out.println("The program has quit.");
                            System.exit(0);
                }
        } while (initialSelection.equalsIgnoreCase(print));

    }else if(initialSelection.equalsIgnoreCase(input)){
        System.out.println("\n Please enter some kind of value (ex: 123, hello, True)");
    }
}

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我相信它来自嵌套的do while语句，但我似乎无法解决这个问题。任何提示都将不胜感激

这是因为你需要

String initialSelection = scan.next();

或

---

如果两者都有，则需要输入两次

，这很有意义。非常感谢！

        boolean stringInput = scan.hasNext();
        boolean intInput = scan.hasNextInt();
        boolean boolinput = scan.hasNextBoolean();