c - scanf single char 不适用于我的循环

Question

所以我一直在编写二维寻宝的代码，其中我使用 scanf 中的单个字符，无论它是 n、s、w、e，它都会执行特定的输出。不幸的是，我的代码没有监听我的输入，例如，当我输入 n 时，什么也没有发生。我想知道你们能否指出我正确的道路

do
{
    printf("Please press n, s, w, or e to find the treasure\n");
    scanf(" %c", &n);
    if (scanf(" %c", &n) == 'n')
    {
        current - 11;
        new = current - 11;
        if (abs(potofgold - current) < abs(potofgold - new))
            printf("getting warmer\n");
        else if (abs(potofgold - current) > abs(potofgold - new))
            printf("Getting colder\n");
        else
            printf("Hooray\n");
        current = new;
    }
    else if (scanf("%c", &s) == 's')
    {
        current + 11;
        new = current + 11;
        if (abs(potofgold - current) < abs(potofgold - new))
            printf("Getting warmer\n");
        else if (abs(potofgold - current) > abs(potofgold - new))
            printf("getting colder\n");
        else
            printf("Hooray\n");
        current = new;
    }
    else if (scanf("%c", e) == 'e')
    {
        current + 1;
        new = current + 1;
        if (abs(potofgold - current) < abs(potofgold - new))
            printf("getting warmer\n");
        else if (abs(potofgold - current) > abs(potofgold - new))
            printf("getting colder\n");
        else
            printf("Hooray\n");
        current = new;
    }
    else (scanf("%c", &w) == 'w');
    {
        current - 1;
        new = current - 1;
        if (abs(potofgold - current) < abs(potofgold - new))
            printf("getting warmer\n");
        else if (abs(potofgold - current) > abs(potofgold - new))
            printf("getting colder\n");
        else
            printf("Hooray\n");

        current = new;
    }
}
while (current != potofgold);

return 0;

Answer 1

这些条件在任何情况下都不会成立 -

if (scanf(" %c", &n) == 'n')       // compare variable with character n=='n' 
....
else if (scanf("%c", &s) == 's')              // s=='s'
....
else if (scanf("%c", e) == 'e')               // e=='e'
                    ^ & missing here

scanf 在每种情况下都会在成功时返回 1 。不要将其与字符进行比较。

相反，您可以编写这样的条件 -

 if (scanf(" %c", &n) == 1 && n=='n')     // if scanf will be successful then only n=='n' will be evaluated. Thus , on failure of scanf scond condition will not be evaluated
  ....
 else if (scanf("%c", &s) ==1 && s=='s')  
 ....
 else if (scanf("%c", &e) == 1 && e=='e')              

这应该是else if-

 else (scanf("%c", &w) == 'w');   // else ends here (It should be else if)
{                                      // this is after else part 
    current - 1;           // remove this , compiler will issue an error\warning
    new = current - 1;     
    if (abs(potofgold - current) < abs(potofgold - new))
        printf("getting warmer\n");
    else if (abs(potofgold - current) > abs(potofgold - new))
        printf("getting colder\n");
    else
        printf("Hooray\n");

    current = new;
}

还有这些

 current - 11;  // do you mean current-=11;
 current + 11;  // as current+=11;
 current +1 ;   // as current +=1;
 current -1 ;   // as current -=1;