检查用户输入是否已经输入

Question

我试图让用户输入一个字符并检查他们之前是否输入过该字符。如果发生这种情况，请他输入他以前未使用过的另一个字符。我的知识仅限于 if 语句和循环，所以如果解决方案是我能理解的，我将不胜感激。

当我输入任何字母时，例如 E，它会将其放入猜测的数组，如果我再次输入 E，它会再次放入猜测的数组，而不是要求用户更改字母。

string check= "";
char wguess ='';
char[] wguess = new char[26];
do
{
    check = Console.ReadLine();

    if (check!="")
    {
        wguess = char.ToUpper(Convert.ToChar(check));
        for (int i = 0; i <= 25; i++)
        {
            if (wguess == guessed[i])
            {
                Console.Write(wguess);
                Console.WriteLine(guessed[i]);
                Console.WriteLine("Please choose a letter you haven't used yet.");
            }
            else
            {
                Console.Write(wguess);
                Console.WriteLine(guessed[i]);
                temp = wguess;
                guessed[i] = wguess;
                wguess = ' ';
            }
        }
    }
    else
    {
        Console.WriteLine("Please Enter a letter.");
    }
} while (check=="");

Output1 = Guessed Letters: E

Output2 = Guessed Letters: EE

Answer 1

您可以使用 Contains 方法，如下所示：

  If(guessed.Contains(wguess)
    { 
       //Whatever happens when the character already has been entered
    }
    else
    {
      //Whatever happens when the character has not been guessed
    }

Answer 2

更改代码如下：

do{
    check = char.ToUpper(Convert.ToChar(Console.ReadKey()));
    if (!guessed.Contains(check))
    {
        // This is new, not in the guessed
    }
    else 
    { 
    // Already entered
    }

} while (check==' ');

检查用户输入是否已经输入

Check if user input was already inputted

c#

if-statement

console-application