if 和 if else 语句有效，但不是 else

Question

我正在制作一个猜数字游戏程序，但我的 else 语句遇到了一些问题。在试图猜测数字的主块中，if 和 if else 语句有效，但 else 语句不执行任何操作。我试图让它在范围之外的数字 0

此外，如果输入“1”，我会尝试让游戏重演，但无论输入什么，程序都会崩溃。

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    /*Number guessing game: The number that needs to be guessed is 52*/
    int guess;
    int attempt = 6;
    int playAgain = 1;

    printf("Guess the integer that I am thinking of between 1 and 100\n");
    printf("I will tell you if you guess too high or too low\n");
    printf("You have 6 attempts\n");
    printf("What is your first guess?\n");
    if (playAgain == 1)
    {
        while (attempt > 0)
        {

            scanf_s("%d", &guess);

            if (guess > 0)
            {
                if (guess < 52)
                {
                    attempt--;
                    printf("Sorry! Too low! You have %d more tries:\n", attempt);
                }
            }
            else if (guess <100)
            {
                if (guess > 52)
                {
                    attempt--;
                    printf("Sorry! Too high! You have %d more tries:\n", attempt);
                }
            }
            else if (guess == 52)
            {
                printf("Correct! You win!\n");
                attempt = 0;
            }

            else
            {
                printf("Invalid input: Please enter an integer between 1 and 100:\n");
            }
        }

        printf("Enter '1' to play again or anything else to terminate\n");
        scanf_s("%d", playAgain);
        attempt = 6;
    }

    else
        {
            printf("Thanks for playing!\n");
        }
    return 0;

}

Answer 1

当您使用不带括号的if else if 时，请确保它不会有歧义。

当你这样做时：

if (true)
   if (true)
   {
   }
else if (false)
{
}

如何知道else if对应的是第一个还是第二个if？这就是为什么每个人都喊你放括号的原因。

if (true)
{
   if (true)
   {
   }
}
else if (false)
{
}

Answer 2

更正和简化的版本：

您的程序崩溃了，因为您忘记了 & 登录scanf("%d", &playAgain);。

你的程序中的逻辑是错误的，如果数字小于、等于或大于输入，则将测试与输入小于 0 或大于 100 的测试混合。

在这个更正的版本中，“无效输入”问题与实际的“数字猜测”问题分开。

此外，要猜测的数字 (52) 不再是硬编码的，而是使用变量 numbertobeguessed。稍后您应该增强程序以便生成随机数。

int main(void)
{
  /*Number guessing game: The number that needs to be guessed is 52*/
  int numbertobeguessed = 52 ;
  int guess;
  int attempt = 6;
  int playAgain = 1;

  printf("Guess the integer that I am thinking of between 1 and 100\n");
  printf("I will tell you if you guess too high or too low\n");
  printf("You have 6 attempts\n");
  printf("What is your first guess?\n");

  if (playAgain == 1)
  {
    while (attempt > 0)
    {
      scanf_s("%d", &guess);

      if (guess < 0 || guess > 100)
      {
        printf("Invalid input: Please enter an integer between 1 and 100:\n");
      }
      else
      {
        if (guess < numbertobeguessed)
        {
          attempt--;
          printf("Sorry! Too low! You have %d more tries:\n", attempt);
        }
        else if (guess > numbertobeguessed)
        {
          attempt--;
          printf("Sorry! Too high! You have %d more tries:\n", attempt);
        }
        else
        {
          printf("Correct! You win!\n");
          attempt = 0;
        }
      }
    }

    printf("Enter '1' to play again or anything else to terminate\n");
    scanf_s("%d", &playAgain);
    attempt = 6;
  }
  else
  {
    printf("Thanks for playing!\n");
  }

  return 0;
}

Answer 3

给出消息"Invalid input: Please enter an integer between 1 and 100:\n" 的else 语句被认为是最内层if-else-if 语句的else 部分。因此，只有在0 < guess < 100 时，才会执行该语句，因为执行进入该if-else-if 语句。因此，请正确使用 {} 来正确组合 if-else 语句。

Answer 4

你的嵌套是错误的。为每个 if 和 else 加上括号以使您的代码工作（快速修复），并使用适当的缩进使其对人类可读（如果您愿意）。

这是一个错误的例子（伪代码）：

a = 4
if (a > 0)
    if (a < 3)
        a = 2
else
    a = 3

你期望 a 的最终值是多少？

不管怎样，你的：

if (guess > 0)
if (guess < 52)

应该变成这样：

if (guess > 0 && guess < 52)

和你的：

else if (guess <100) // this is where the problems start
if (guess > 52)

应该变成：

else if (guess < 100 && guess > 52)

你的代码就可以工作了。

Answer 5

希望对你有帮助

#include <stdio.h>
#include <stdlib.h>

int main()
{
   int guess; //variable to hold the number from player
   int attempts = 6;
   char play = 'y';

   do
   {

    while(attempts)
   { 
     printf("\nEnter you guess: "); scanf("%d", &guess);

     attempts--;

     if(guess>0 && guess <100 )
     {
        if(guess>52)
          printf("\nThat's not it. Try something lower than that.");
        else if(guess<52)
          printf("\nThat's not the number. Try something higher than that.");
        else if(guess==52)
        { printf("\nYou got it!. You won the game."); 
          attempts = 0; //we're setting it to zero; we don't want the loop to run anymore
        }
     }
     else 
       printf("\nNumber enter is not in range!");
   }//end of while loop

     printf("\nDo you want to play again? (y/n): "); scanf("%c", &play);
   }while(play=='y' || play=='Y'); //run till player enter 'Y'
   return 0;
}