c - 为什么这个 C 循环会跳过第一次输入字母的尝试？

Question

这是我为类制作的程序。它应该从文件中读取一个字母，然后在游戏中用户尝试猜测这个字母。对于每一次错误的尝试，程序都会告诉您实际字母是在字母表中您猜测的之前还是之后。

由于某种原因，当我运行它时，循环跳过了 getLetter 函数中的第一次尝试，并且不允许您输入字母。这是为什么？

#include <stdio.h>
#include <ctype.h>
#define MaxGuesses 5

void instructions();
int playGuess (char solution);
char getLetter ();
int compareLetters (char guess, char solution);

int main()
{

     int numGames;
     int i;
     char solution;
     char guess;
     int result;

     FILE *inFile;

     inFile=fopen("inputLet.txt","r");

     instructions();
     scanf("%d", &numGames);

     for(i=1; i<=numGames; i++)
     {
         printf ("\nThis is game %d\n", i);
         fscanf(inFile, " %c", &solution);
         result = playGuess(solution);

         if (result == 1)
             printf("You've WON!\n");
         else
             printf("You've LOST :(\n");

     }

     //close file
     fclose(inFile);
     return 0;
      }

      void instructions ()
      {
          printf ("This game consists of guessing letters.\nThe user will have up      to 5 chances of guessing correctly,\nupon every failed attempt,\na hint will be provided  regarding alphabetical position.\n\nEnter the number of games you wish to play (max 4): ");
 }

 char getLetter()
 {
     char userGuess;
     printf("\nPlease enter your guess: ");
     scanf("%c", &userGuess);
     userGuess = tolower(userGuess);
     return userGuess;
 }

 int compareLetters(char guess, char solution)
 {
     if (guess == solution)
         return 1;
     else if (guess < solution)
    {
         printf("\nThe letter that you are trying to guess comes before %c",    guess);
    return 0;
}
else if (guess > solution)
{
    printf("\nThe letter that you are trying to guess comes after %c", guess);
    return 0;
}
 }

 int playGuess (char solution)
 {
     int numGuesses = 0;
     int winOrLose = 0;
     char guess;
     while(numGuesses < MaxGuesses && winOrLose == 0)
     {
         guess = getLetter();
         winOrLose = compareLetters(guess, solution);
         numGuesses++;  
     }

     return winOrLose;
 }

Answer 1

它可能正在消耗输入缓冲区中剩余的字符(可能是换行符或其他空白字符)。您可以尝试将格式字符串从 "%c" 更改为 "%c" ，就像您在其他地方所做的那样，这将在尝试之前跳过缓冲区中的所有空白字符读取一个字符。