如何从一个操作中排除多个值？ 我是否可以将or运算符与if else语句一起使用？

Question

我知道如果只使用连续数字会更容易，但是我想使用户更容易选择与他们选择的模具类型相对应的数字。 如果使用or运算符，我是否只能比较两件事？ 这是我试图做的，但是没有用。 我的语法错误吗？或者我不能在一个语句中将多个术语字符串化吗？：

if (typeOfDice != 4 || typeOfDice != 6 || 
        typeOfDice != 8 || typeOfDice != //10 || typeOfDice != 12 || 
        typeOfDice != 20 || typeOfDice != 100)

这是我要使其运行的简短程序。我只想确保用户不会破坏该程序：

    static void Main(string[] args)
    {
        Start:
        Random roll = new Random();

        // Request dice type from user
        Console.WriteLine("Please input the type of dice you want to roll. ");

        // Display dice types to user
        Console.WriteLine("4) Four-sided");
        Console.WriteLine("6) Six-sided");
        Console.WriteLine("8) Eight-sided");
        Console.WriteLine("10) Ten-sided");
        Console.WriteLine("12) Twelve-sided");
        Console.WriteLine("20) Twenty-sided");
        Console.WriteLine("100) Percentage");
        Console.WriteLine(" ");

        // Take dice type from user
        Console.Write("Type of Dice: ");
        int typeOfDice = Convert.ToInt32(Console.ReadLine());
        Console.WriteLine(" ");

        // Prevents user from breaking the program by printing a corrective message
        // and restarting the program in the event an inappropriate choice is made by the user.
        if (typeOfDice != 4 || typeOfDice != 6 ||
        typeOfDice != 8 || typeOfDice != //10 || typeOfDice != 12 || 
        typeOfDice != 20 || typeOfDice != 100)
            Console.WriteLine("That is not an acceptable die type. Please try again.");
        goto Start;
        else
        {

            // Initiates random variable and total variable
            Random rnd = new Random();
            int total = 0;

            // Request number of dice from user
            Console.WriteLine("Please input the number of dice you want to roll ");
            Console.WriteLine(" ");

            // Accept number of dice from user 
            Console.Write("Number of Dice: ");
            int numberOfDice = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine(" ");

            /// Assigns random generator parameters to user's choice of dice type and 
            // generates random number, looping until the die is rolled the requested 
            // number of times and the result of each new roll is added to the total
            switch (typeOfDice)
            {

                case 4:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

                case 6:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

                case 8:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

                case 10:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

                case 12:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

                case 20:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        // Console.WriteLine(" ");

                    }
                    break;

                case 100:
                    for (int count = 0; count < numberOfDice; count++)
                    {

                        int currentRoll = rnd.Next(typeOfDice);
                        total += currentRoll + 1;
                        Console.Write("{0} ", currentRoll + 1);
                        //Console.WriteLine(" ");

                    }
                    break;

            }

            // Prints total of dice rolls.
            Console.WriteLine(" ");
            Console.WriteLine("Total: {0}", total);
            Console.WriteLine(" ");

            goto Start;
        }

    }

Answer 1

您希望测试之间使用&&（逻辑AND）而不是|| （逻辑或）

if (typeOfDice != 4 && 
    typeOfDice != 6 && 
    typeOfDice != 8 && 
    typeOfDice != 10 && 
    typeOfDice != 12 && 
    typeOfDice != 20 && 
    typeOfDice != 100)

与|| operator || operator ，如果您为骰子选择了正确的值，则if评估始终为true。
例如，假设您的用户选择一个骰子= 4，现在此骰子值（4）与骰子值6（或其他可接受的值）不同，因此您的条件将始终找到一个为true的条件，并且您的代码将输出错误信息

我也想向您介绍enum关键字。

public enum DiceType
{
   FourSides = 4,
   SixSides= 6,
   EightSides = 8,
   TenSides = 10,
   TwelveSides = 12,
   TwentySides = 20,
   Percentage = 100
}

现在，您可以使用此枚举类型的变量，而不是使用幻数

Random roll = new Random();
while(true)
{
    // Request dice type from user
    Console.WriteLine("Please input the type of dice you want to roll. ");

    // Display dice types to user
    Console.WriteLine("4) Four-sided");
    Console.WriteLine("6) Six-sided");
    Console.WriteLine("8) Eight-sided");
    Console.WriteLine("10) Ten-sided");
    Console.WriteLine("12) Twelve-sided");
    Console.WriteLine("20) Twenty-sided");
    Console.WriteLine("100) Percentage");
    Console.WriteLine(" ");
    Console.WriteLine("Type quit to exit ");

    // Take dice type from user
    Console.Write("Type of Dice: ");
    string input = Console.ReadLine();
    if(input == "quit")
       break;

    DiceType typeOfDice;

    // Try to parse the input and check if it could be an enum of the 
    // desidered type (Note user can also input "foursides" not just 4
    if (!Enum.TryParse<DiceType>(input, true, out typeOfDice) || 
        !Enum.IsDefined(typeof(DiceType), typeOfDice))
        Console.WriteLine("That is not an acceptable die type. Please try again.");
    else
    {
       ....
       switch (typeOfDice)
       {
           case DiceType.FourSides:
               .....
               break;
           case DiceType.SixSides:
               .....
               break;

           ....
        }
    }
}

我还删除了goto代码。 我没有在代码中添加无限循环，而没有采用这种著名的坏习惯。 菜单中的新选项（退出）允许您的用户退出循环并终止程序