c - 做一会儿还是一会儿？

Question

我试图让我的程序仅在用户输入 Y 或 y 时运行，但它只运行一次，即使它不是 Y 或 y。输入将为 Y、y、N 或 n

printf("Welcome to the Jumble Puzzle Solver!\n\n");
printf("Would you like to enter a jumbled word?\n");
scanf("%s", &answer);


    do{

    printf("What word would you like scored?\n");
    scanf("%s", &letters);

    strcpy(changeletters, letters);

    recursivepermute(letters, changeletters, checkword, k, dictionary ,max, min);

    printf("Would you like to enter a jumbled word?\n");
    scanf("%s", &answer);

    }while (answer == 'Y' || answer == 'y');

Answer 1

do { } while() 导致主体始终至少执行一次。如果您想先检查条件，只需使用 while:

// If answer is:
// char answer;

scanf("%c", &answer);
while (answer == 'Y' || answer == 'y')
{
     printf("What word would you like scored?\n");
    // ...

    scanf("%c", &answer);
}

如果 answer 是 char，您还需要使用 scanf("%c"。%s 是扫描一串字符(即:char[20])，并且需要使用类似 strcmp 或类似的方法进行不同的检查。