c# - 如何将字母转换为数字并打印出 BTEC 最终成绩

Question

我正在为那些不了解的人设计一个 BTEC 成绩计算器； BTEC 是在英国完成的一种资格认证，具有主要基于类(class)作业的“不同”评分系统。有许多单元 (20)，每个单元您可以获得每个单元的及格、优点和区别。每一次通过、优点和区别加起来这么多分，这些分加起来就是总成绩。

例如，120 分将映射到 PPP 等级，240 分将映射到 MMM 等等。

我已经根据以下伪代码编写了一个程序:

Prompt for student name:
Operator enters student name
Operator enters their grade units one at a time (D, M, P, D etc):
Display Message about final grade:
    Your final Grade is:
    DMM

以下是我当前的代码，但需要更改和修复。目前，我需要以数字 (20, 40) 的形式输入单元成绩。我希望能够输入等级字母 (D、M、P)。如何更改我的程序，以便它可以解释字母并将它们映射到单元分数？

我还遇到了从最终分数转换为最终成绩的问题。目前，如果我输入两个单元成绩 80，总分 160，显示的成绩应该是 MPP，但它打印的是 120。我做错了什么？

class Program
{
    static void Main(string[] args)
    {
        int counter;
        double score;

        while (true)
        {
            counter = 1;
            score = 0.0;
            Console.WriteLine("Enter Your Name or type 'exit' to quit): ");
            // Naming for exiting 
            string name = Console.ReadLine();
            if (name == "exit")
            {
                Environment.Exit(0);
            }
            else
            {
                int numberOfUnits = 20;
                Console.WriteLine("Number of Units:  ");
                numberOfUnits = int.Parse(Console.ReadLine());

                while (counter <= numberOfUnits)
                {
                    Console.WriteLine("Final Grade Score {0}", counter);
                    score += double.Parse(Console.ReadLine());
                    counter++;
                }
                // Add up and print letter grade. 
                score = (score / (counter - 1));
                if (score < 120)
                {
                    Console.WriteLine("Letter Grade: PPP");
                }
                else if (score < 160)
                {
                    Console.WriteLine("Letter Grade: MPP");
                }
                else if (score < 200)
                {
                    Console.WriteLine("Letter Grade: MMP");
                }
                else if (score < 240)
                {
                    Console.WriteLine("Letter Grade: MMM");
                }
                else if (score < 280)
                {
                    Console.WriteLine("Letter Grade: DMM");
                }
                else if (score < 320)
                {
                    Console.WriteLine("Letter Grade: DDM");
                }
                else if (score < 360)
                {
                    Console.WriteLine("Letter Grade: DDD");
                }
                    // After DDD it goes up by 20's ..... D* = 20 not 40...
                else if (score < 380)
                {
                    Console.WriteLine("Letter Grade: D*DD");
                }
                else if (score < 400)
                {
                    Console.WriteLine("Letter Grade: D*D*D");
                }
                else if (score < 420)
                {
                    Console.WriteLine("Letter Grade: D*D*D*");
                }
                Console.WriteLine("Grade: {0}", (score).ToString("P"));
            }
        }
    }
}

Answer 1

这是经过一些小改动的代码，以及将字母转换为数字的 switch 语句。

public class Program
{
    static void Main(string[] args)
    {
        int counter;
        double score;

        while (true)
        {
            counter = 1;
            score = 0.0;
            Console.WriteLine("Enter Your Name or type 'exit' to quit): ");
            // Naming for exiting 
            string name = Console.ReadLine();
            if (name == "exit")
            {
                return;
            }
            else
            {
                int numberOfUnits = 20;
                Console.WriteLine("Number of Units:  ");
                numberOfUnits = int.Parse(Console.ReadLine());

                while (counter <= numberOfUnits)
                {
                    Console.WriteLine("Final Grade Score {0}", counter);
                    string s = Console.ReadLine().ToUpper();
                    double d;
                    if (double.TryParse(s, out d)) //parsing as a number was successfull, and the result is in d.
                        score += d;
                    else //parsing failed.
                    {
                        switch (s)
                        {
                            case "D":
                                score += 20;
                                break;
                            case "M":
                                score += 50;
                                break;
                            case "P":
                                score += 70;
                                break;
                            default:
                                counter--; //parsing of a letter failed. reducing counter that will be later incremented, to offset the effect.
                                Console.WriteLine("Could not parse your grade. Enter a number or a letter");
                                break;
                        }
                    }
                    counter++;
                }
                // Add up and print letter grade. 
                score = (score / (counter - 1));

                if (score < 120) Console.WriteLine("Letter Grade: PPP");
                else if (score < 160) Console.WriteLine("Letter Grade: MPP");
                else if (score < 200) Console.WriteLine("Letter Grade: MMP");
                else if (score < 240) Console.WriteLine("Letter Grade: MMM");
                else if (score < 280) Console.WriteLine("Letter Grade: DMM");
                else if (score < 320) Console.WriteLine("Letter Grade: DDM");
                else if (score < 360) Console.WriteLine("Letter Grade: DDD");
                // After DDD it goes up by 20's ..... D* = 20 not 40...
                else if (score < 380) Console.WriteLine("Letter Grade: D*DD");
                else if (score < 400) Console.WriteLine("Letter Grade: D*D*D");
                else if (score < 420) Console.WriteLine("Letter Grade: D*D*D*");
                Console.WriteLine("Grade: {0}", (score).ToString("P"));
            }
        }
    }
}