Question

     while(flag)
     {       
        System.out.println("Press 1 to Add Student details");
        System.out.println("Press 2 to Display Student details");
        System.out.println("Press 3 to Sort");
        System.out.println("Press 4 to Search");
        System.out.println("Press 5 to Exit");
        System.out.println("Enter your choice: ");

        while(!sc1.hasNextInt())
        {
            System.out.println("Please enter proper Integer input!");
            sc1.next();
        }

        choice = sc1.nextInt();
      //more code..
    }

在上面的代码中，我正在接受用户的输入。如果用户输入除int之外的任何内容，则不接受。假设，给出一个字符串而不是int，打印消息并且不再显示菜单。我想在消息后显示菜单。我该怎么做？

Answer 1

这可能对您有所帮助

while (flag) {
    System.out.println("Press 1 to Add Student details");
    System.out.println("Press 2 to Display Student details");
    System.out.println("Press 3 to Sort");
    System.out.println("Press 4 to Search");
    System.out.println("Press 5 to Exit");
    System.out.println("Enter your choice: ");

    if (sc1.hasNextInt()) {
        choice = sc1.nextInt();
        //more code here
    } else {
        System.out.println("Please enter proper Integer input!\n");
        sc1.next();
    }
}

我添加了额外的"\n"以提高可读性。因此，当打印警告时，选项将不会在下一行打印。

Answer 2

您还需要在内部循环中使用菜单sysouts。像这样： -

while(!sc1.hasNextInt())
{
    System.out.println("Please enter proper Integer input!");
    System.out.println("Press 1 to Add Student details");
    System.out.println("Press 2 to Display Student details");
    System.out.println("Press 3 to Sort");
    System.out.println("Press 4 to Search");
    System.out.println("Press 5 to Exit");
    System.out.println("Enter your choice: ");
    sc1.next();
}

如何再次打印菜单选项？

2 个答案: