C# Scrabble程序故障求助：单字母计分正常，整词输入报错

我曾尝试用自定义函数实现Scrabble计分程序，但没成功，于是重写了代码。现在单个字母输入能正常计算分数，但输入完整单词时会出错。请问该怎么修复这个问题，或是我是否应该重新采用函数实现方式？

新代码 #

string Word = "";
int score = 0;

Console.WriteLine("Enter a word");
Word = Console.ReadLine();
Word.ToUpper();

string[] arrOneP = new string[] { "A", "O", "I", "U", "R", "S", "E", "T", "N", "L" };
string[] arrTwoP = new string[] { "D", "G" };
string[] arrThreeP = new string[] { "B", "C", "M", "P" };
string[] arrFourP = new string[] { "F", "H", "W", "Y", "V" };
string[] arrFiveP = new string[] { "K" };
string[] arrEightP = new string[] { "J", "X" };
string[] arrTenP = new string[] { "Q", "Z" };

for (int i = 0; i < Word.Length; i++)
{
    if (Word == arrOneP[i])
    {
        score = score + 1;
    }
    else if (Word == arrTwoP[i])
    {
        score = score + 2;
    }
    
    else if(Word == arrThreeP[i])
    {
        score = score + 3;
    }

    else if (Word == arrFourP[i])
    {
        score = score + 4;
    }
    
    else if (Word == arrFiveP[i])
    {
        score = score + 5;
    }

    else if (Word == arrEightP[i])
    {
        score = score + 8;
    }

    else if (Word == arrTenP[i])
    {
        score = score + 10;
    }
}    

Console.WriteLine(score);

旧代码 #

namespace Scrabble
{
internal class Program
{
static void Main(string[] args)
{
string Word = "";
int score = 0;
int WordValue = 0;

Console.WriteLine("Enter a word");
Word = Console.ReadLine();

static int CalcVal(char letter)
{
    string[] arrOneP = new string[] { "A", "O", "I", "U", "R", "S", "E", "T", "N", "L" };
    string[] arrTwoP = new string[] { "D", "G" };
    string[] arrThreeP = new string[] { "B", "C", "M", "P" };
    string[] arrFourP = new string[] { "F", "H", "W", "Y", "V" };
    string[] arrFiveP = new string[] { "K" };
    string[] arrEightP = new string[] { "J", "X" };
    string[] arrTenP = new string[] { "Q", "Z" };

    for (int i = 0; i < arrOneP.Length; i++)
    {
        if (i == arrOneP.Length)
        {
            return 1;
        }
    }
    
    for (int i = 0; i < arrTwoP.Length; i++)
    {
        if (i == arrTwoP.Length)
        {
            return 2;
        }
    }
    
    for (int i = 0; i < arrThreeP.Length; i++)
    {
        if (i == arrThreeP.Length)
        {
            return 3;
        }
    }

    for (int i = 0; i < arrFourP.Length; i++)
    {
        if (i == arrFourP.Length)
        {
            return 4;
        }
    }

    for (int i = 0; i < arrFiveP.Length; i++)
    {
        if (i == arrFiveP.Length)
        {
            return 5;
        }
    }

    for (int i = 0; i < arrEightP.Length; i++)
    {
        if (i == arrEightP.Length)
        {
            return 8;
        }
    }

    for (int i = 0; i < arrTenP.Length; i++)
    {
        if (i == arrTenP.Length)
        {
            return 10;
        }
    }
  
    Console.WriteLine("Your score is {0}", CalcVal);
}
}
}

问题分析与修复方案 #

新代码的核心问题 #

1. 字符串转大写未生效：C#字符串是不可变类型，Word.ToUpper()不会修改原字符串，必须重新赋值：Word = Word.ToUpper();
2. 比较逻辑错误：循环中拿整个Word和数组元素比较，应该取当前循环的单个字符Word[i]，同时要统一类型（数组是string，字符是char，可将数组改为char[]，或把字符转成string）
3. 索引越界风险：当单词长度超过某个分值数组的长度时（比如单词长度11，arrOneP仅10个元素），arrOneP[i]会触发索引越界异常，因为循环变量i基于单词长度而非数组长度。

修复后的优化版代码 #

用Dictionary<char, int>存储字母与分值的对应关系，查找效率更高，代码更简洁：

string word = "";
int score = 0;

Console.WriteLine("Enter a word");
word = Console.ReadLine()?.ToUpper() ?? "";

// 定义字母分值映射
var letterScores = new Dictionary<char, int>
{
    {'A',1}, {'O',1}, {'I',1}, {'U',1}, {'R',1}, {'S',1}, {'E',1}, {'T',1}, {'N',1}, {'L',1},
    {'D',2}, {'G',2},
    {'B',3}, {'C',3}, {'M',3}, {'P',3},
    {'F',4}, {'H',4}, {'W',4}, {'Y',4}, {'V',4},
    {'K',5},
    {'J',8}, {'X',8},
    {'Q',10}, {'Z',10}
};

foreach (char c in word)
{
    if (letterScores.TryGetValue(c, out int value))
    {
        score += value;
    }
    // 可选：处理非字母字符，比如忽略或提示
}

Console.WriteLine(score);

是否应该采用函数实现？ #

非常推荐用函数封装计分逻辑，代码结构更清晰，方便复用和维护。比如把单个字母计分的逻辑抽成函数：

static int GetLetterScore(char letter)
{
    letter = char.ToUpper(letter);
    return letter switch
    {
        'A' or 'O' or 'I' or 'U' or 'R' or 'S' or 'E' or 'T' or 'N' or 'L' => 1,
        'D' or 'G' => 2,
        'B' or 'C' or 'M' or 'P' => 3,
        'F' or 'H' or 'W' or 'Y' or 'V' => 4,
        'K' => 5,
        'J' or 'X' => 8,
        'Q' or 'Z' => 10,
        _ => 0 // 非字母字符计0分
    };
}

// 在Main中调用：
foreach (char c in word)
{
    score += GetLetterScore(c);
}

这种写法的可读性和可维护性远高于原版本，也避免了旧代码中循环逻辑的错误（旧代码的循环永远不会触发返回，因为i永远不会等于数组长度）。

内容的提问来源于stack exchange，提问作者Gene