Question

所以这是我的代码：

#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h> 
#define MAX_GUESSES 4
int PlayGame(char guess);
int WinOrLose(char userguess, char solution);
int main()
{
        FILE* infile;
    char correctlet;
    int games,
        igame,
        result;
    infile = fopen("inputLet.txt", "r");
    printf ("Welcome to the letter guessing game!\n");
    printf ("Your job is to guess a random letter.\n");
    printf("You can guess each letter a maximum of 4 times,\n");
    printf ("and you will get a hint after every guess.\n");
    printf ("LET'S DO THIS!\n\n>");
    printf ("\nHow many games would you like to play (1-3)?\n>");
    scanf ("%d",&games);
    for(igame=0;igame<games;igame++)
    {
        fscanf(infile," %c",&correctlet);
        printf("This is game %d\n", igame+1);
        result = PlayGame (correctlet);
        if (result == 0)
        {
            printf ("\nCongratulations, you guessed the right letter!\n");
        }
        else
        {
            printf ("\nUnfortunately, you did not guess the right letter. Better luck next time!\n");
    }
    }
    return 0;
}
int PlayGame(char solution)
{
    int guessnumber,
        result;
    char userguess;
    guessnumber = 0;
    while(guessnumber < MAX_GUESSES)
    {
        printf("Please enter your guess\n>");
        scanf("%c", &userguess);
        if (sizeof userguess == 0)
        {
            continue;
        }
        else if (sizeof userguess >=1)
    {
        printf ("Your guess was %c\n",userguess);
        result = WinOrLose (userguess, solution);
        if (result == 0)
        {
            return 0;
            break;
        }
        else if (result == 1)
        {
            if (solution < userguess)
            {
                printf("The correct letter comes before %c alphabetically\n", userguess);
            }
            else if (solution > userguess)
            {
                printf("The correct letter comes after %c alphabetically\n", userguess);
            }
        guessnumber ++;
        }
    }
}
}
int WinOrLose (char userguess, char solution)
{
    if(solution==userguess)
    {
        return 0;
    }
    else if (solution != userguess)
{
    return 1;
}
}

输出请求游戏数量，然后输出请输入您的猜测您的猜测是（空白）正确的字母后来（空白）请输入您的猜测然后它允许用户输入。那么为什么在没有要求用户输入的情况下进行一次PlayGame迭代呢？我已经尝试了我能想到的一切，无法解决问题。我正在编译VC ++ 2010，如果这有帮助的话。提前谢谢！

Answer 1

简单的回答是刷新缓冲区。

stdin缓冲区，从键盘（或管道）获取指令并将其提交给程序的缓冲区偶尔会出现一些字符＆＃34;卡住＆＃34;在里面。从未完全提交的垃圾字符，额外的退货等会导致scanf（）认为它达到了正确的结果，但实际上并没有。

fflush(stdin);

功能fflush＆＃34;刷新＆＃34;一个缓冲区。这样做的效果是消耗来自缓冲区的数据，直到收到的数据是字符“0”和“0”。（空值）。这意味着它已到达当前缓冲区中的最后一个数据。

在调用scanf（）之前调用它意味着当调用scanf（）时，你有理由知道程序将在scanf（）上阻塞，直到你提交，而不只是从缓冲区消耗一些垃圾。

信猜猜游戏奇怪的输出

1 个答案: