Question

感谢所有答案，这真的帮助了我！

但是我遇到了一个新问题......在我写的程序中，要求用户键入不同数学问题的答案，并且控制台会在每个问题后说出答案是正确还是不正确。最后，程序将显示有多少用户答案的百分比是正确的，这是我遇到了问题。

Console.Write("How many questions would you like to answer (Maximum value is '100'): ");
        string input = Console.ReadLine();
        int questionsAmount = int.Parse(input);

        int correctAnswers = 0;
        int IncorrectAnswers = 0;

        for (int i = 1; i <= questionsAmount; i++)
        {
            Console.WriteLine("===================");
            Console.WriteLine("Question " + i);
            Console.WriteLine();

            Random rnd = new Random();
            int rndNumber = rnd.Next(1, 100);
            int rndNumber2 = rnd.Next(1, 100);

            Console.Write("What equals " + rndNumber + " + " + rndNumber2 + " = ");
            string input2 = Console.ReadLine();
            int answer = int.Parse(input2);

            if (answer == rndNumber + rndNumber2)
            {
                correctAnswers++;
                Console.WriteLine("Answer correct.");
                Console.WriteLine("Correct answers: " + correctAnswers);
            }
            else
            {
                IncorrectAnswers++;
                Console.WriteLine("Answer incorrect.");
                Console.WriteLine("Incorrect answers: " + IncorrectAnswers);
            }
        }
        double percentage = correctAnswers / questionsAmount * 100;
        Console.WriteLine(percentage + "% of your answers was correct");

如您所见，一旦所有问题都得到解答，它将计算百分比，但由于我已经分配了变量＆＃39; correctAnswers＆＃39;对于值＆＃39; 0＆＃39;，计算将如下所示：0 / x * 100 = 0

如果我把变量＆＃39; correctAnswers＆＃39;和＆＃39;不正确的答案＆＃39;在for-statement行double percentage = correctAnswers / questionsAmount * 100;内行不通。

Answer 1

只有在抛出异常时才会执行catch子句。你想要的是提出错误答案＆＃34;普通while (true) { try { Console.Write("What equals " + rndNumber1 + " + " + rndNumber2 + ": "); string input = Console.ReadLine(); int answer = int.Parse(input); if (answer == rndNumber1 + rndNumber2) { Console.WriteLine("Your answer is correct."); break; } else { Console.WriteLine("Your answer is incorrect. Try again."); Console.ReadLine(); } } catch { { Console.WriteLine("Sorry, something went wrong."); } } }子句中的逻辑。

bitwise and

Answer 2

您正在寻找else块，而不是catch块：

while (true)
{
    Console.Write("What equals " + rndNumber1 + " + " + rndNumber2 + ": ");
    string input = Console.ReadLine();
    int answer = int.Parse(input);

    if (answer == rndNumber1 + rndNumber2)
    {
        Console.WriteLine("Your answer is correct.");
        break;
    }
    else
    {
        Console.WriteLine("Your answer is incorrect. Try again.");
    }
}

Try / catch用于处理例外，而非应用程序逻辑。 if else与catch配对，而不与int.Parse()配对。

例如，如果您尝试catch一个不是整数的值（例如一串字母），那么将抛出一个异常，你可以在int.TryParse()块中处理。（或使用<div class="flextable table-actions"> <div class="flextable-item" style="padding-right:5px;"> <div class="btn-toolbar-item input-with-icon"> <button type="button" class="btn btn-xs btn-primary-outline" data-target="#addBudgetOriginal" data-toggle="modal">Original Budget</button> </div> </div> <div class="flextable-item" style="padding-right:5px;"> <div class="btn-toolbar-item input-with-icon"> <button type="button" class="btn btn-xs btn-primary-outline" data-target="#myModal" data-toggle="modal">Approved Budget Change</button> </div> </div> <div class="flextable-item" style="padding-right:5px;"> <div class="btn-toolbar-item input-with-icon"> <button type="button" class="btn btn-xs btn-primary-outline" data-target="#addBudget" data-toggle="modal">Budget Reallocation</button> </div> </div> <div class="flextable-item flextable-primary"> <div class="btn-toolbar-item input-with-icon"> <button type="button" class="btn btn-xs btn-primary-outline" data-target="#addBudget" data-toggle="modal">Pending Budget Reduction</button> </div> </div>来避免异常。）

Answer 3

放置可能在try块中抛出异常的代码部分，并放置处理catch块中异常的代码。 catch块是一系列以关键字catch开头的语句，后跟异常类型和要采取的操作您可以输出错误答案＆＃34;提示在else部分，如下所示。尝试并捕获statemnts是为了执行代码行异常。你正在测试的是代码执行中的异常。它只是一个不等于另一个的变量。

 {
            Random rnd = new Random();
            int rndNumber1 = rnd.Next(1, 100);
            int rndNumber2 = rnd.Next(1, 100);

            while (true)
            {
                try
                {
                    Console.Write("What equals " + rndNumber1 + " + " + rndNumber2 + ": ");
                    string input = Console.ReadLine();
                    int answer = int.Parse(input);

                    if (answer == rndNumber1 + rndNumber2)
                    {
                        Console.WriteLine("Your answer is correct.");
                        break;
                    }else{
     Console.WriteLine("Your answer is incorrect. Try again.");
    }
                }
                catch
                {

                }
            }
        }

Answer 4

try...catch控制块用于处理exeptions，这意味着当加密意外错误时代码将跳转到cath部分。在您的代码中，只有在抛出运行时错误时，才会执行此部分Console.WriteLine("Your answer is correct.");。 int.Parse()无法解析该值。

当您尝试比较值时，应使用if流结构

{
    Random rnd = new Random();
    int rndNumber1 = rnd.Next(1, 100);
    int rndNumber2 = rnd.Next(1, 100);

    while (true)
    {
            Console.Write("What equals " + rndNumber1 + " + " + rndNumber2 + ": ");
            string input = Console.ReadLine();
            int answer = int.Parse(input);

            if (answer == rndNumber1 + rndNumber2)
            {
                Console.WriteLine("Your answer is correct.");
                break;
            }
            else
            {
                Console.WriteLine("Your answer is incorrect. Try again.");
            }
    }
}

代码无法计算百分比

4 个答案: