Question

我正在尝试编写一个程序，在该程序中，用户将首先显示一个菜单，从中可以选择多个选项。我试图创建一个代码，一旦选择了一个选项，将返回用户菜单。但是，程序只是结束而不是将用户循环回菜单。我需要将什么添加到代码中，以便一旦选择方法运行它将使用户返回选择菜单？

以下摘要显示了该计划的相关部分：

    Scanner scanner = new Scanner(System.in);

    int selection = 0;


    while (x == 0) {
        System.out.println("Please make a selection");
        System.out.println("[1] Make a new booking");
        System.out.println("[2] View films");
        System.out.println("[3] View Screens");
        System.out.println("[4] View Customers");
        System.out.println("[5] View showing information");
        System.out.println("[6] View booking information");
        System.out.println("[7] Exit");

        while (selection == 0) {
            System.out.println("Selection: ");
            try {
                selection = scanner.nextInt();

            } catch (InputMismatchException nfe) {
                System.out.println("Input must be a number");
                selection = 0;
                scanner = null;
                scanner = new Scanner(System.in);
            }
        }
        switch (selection) {

            case 1:

                System.out.println("All available showings:");
                x = 1;

                for (Showing aShowing : showingList) {
                    System.out.println(aShowing.toString());
                }

                System.out.println("Enter the showing number: ");
                int show = scanner.nextInt();

                Showing userChoice = showingList.get(show - 1);

                System.out.println("Enter the number of tickets: ");

                int tickets = scanner.nextInt();


                Booking booking1 = new Booking(customerA, userChoice, tickets);

                System.out.println(booking1);


                break;

            case 2:
                System.out.println("Current films being shown:");
                x = 1;
                System.out.println("Film one: " + filmA.getTitle()
                        + ".\nLength: " + filmA.getDuration() + " minutes."
                        + "\nAge Rating: " + filmA.getAgeRating()
                        + ".\nDescription: " + filmA.getDescription() + ".");
                break;

            case 3:
                System.out.println("Screen information:");
                x = 1;
                System.out.println("Screen id:" + screenA.getId()
                        + ".\nSeats a maximum of " + screenA.getCapacity() + " people.");
                break;

Answer 1

我不明白while(x==0)在那里做了什么。

我从您的要求中了解到，您希望为用户提供一个菜单，其中包含选项和用户需要输入他的选择，然后将根据该操作执行操作，然后再次请求用户提供其他输入。

如果是这种情况，那么尝试按照以下方式编写逻辑，

do{
    System.out.println("Please make a selection");
    System.out.println("[1] Make a new booking");
    System.out.println("[2] View films");
    System.out.println("[3] View Screens");
    System.out.println("[4] View Customers");
    System.out.println("[5] View showing information");
    System.out.println("[6] View booking information");
    System.out.println("[7] Exit");

    selection = scanner.nextInt();

    switch(selection){

        case 1:
           ...
        //so on

        case 7:
           //do nothing
           break;
        default:
           System.out.println("Wrong number entered");

    }



}while(selection!=7);

在java程序中创建一个循环

1 个答案: