纸板.c :12:1: warning: control reaches end of non-void function [-Wreturn-type]

Question

当我编译代码时，程序下面的两个连接函数无法正常工作。当我在我的电脑上编译代码时，一旦加载其中一个板并返回主菜单，选项 1-2 就可以正常工作，但我无法使用第三个选项，但我没有收到任何错误。换句话说，我无法退出游戏。相反，它会打印“再见!”并要求我选择一个选项。仅当我进入“do while”循环并选择第三个选项时才会发生这种情况。当我在终端中编译代码时，我以某种方式收到标题中提供的错误消息。终端中也会出现同样的错误。有什么想法如何解决这个问题吗？如果需要，我可以提供额外的代码片段。

第一个:

int main() {

printf("Welcome to Car Board \n");
printf("-------------------- \n");
printf("1. Play game \n");
printf("2. Show student's information \n");
printf("3. Quit \n\n");

showMenu();

}

void showMenu(){
  Cell board[BOARD_HEIGHT][BOARD_WIDTH];
  int choice = validateNumber();
  if(choice == 1){

    showCommands();
    initialiseBoard(board);
    displayBoard(board, NULL);

    printf("load <g>\n");
    printf("quit\n\n");

    playGame();

  }

  if (choice == 2){

    showStudentInformation();

  }

  if (choice == 3){

    printf("Good Bye!\n\n");

}

  else showMenu();
}

第二个:

void playGame()
{
  Cell board[BOARD_HEIGHT][BOARD_WIDTH];
  char str1[] = {"load 1"};
  char str2[] = {"load 2"};
  char str3[] = {"quit"};
  char * choice;


do {
    choice = validateString();
    if (strcmp(choice, str1) == 0) {

        printf("\n");
        loadBoard(board, BOARD_1);
        displayBoard(board, NULL);
        playGame();

    }

    if(strcmp(choice, str2) == 0){

        printf("\n");
        loadBoard(board, BOARD_2);
        displayBoard(board, NULL);
        playGame();

    }

    if(strcmp(choice, str3) == 0){

        printf("\n");
        printf("Welcome to Car Board \n");
        printf("-------------------- \n");
        printf("1. Play game \n");
        printf("2. Show student's information \n");
        printf("3. Quit \n\n");
        showMenu();

    }

    else {
        printf("Invalid input\n\n");
        playGame();

    }

}
while(strcmp(choice, str1) != 0 && strcmp(choice, str2) != 0 && strcmp(choice, str3) != 0);


}

Answer 1

尝试在 main 末尾添加 return 0 以消除警告

此外，您应该摆脱所有递归调用。而不是

void showMenu(){
    Cell board[BOARD_HEIGHT][BOARD_WIDTH];
    int choice = validateNumber();
    if(choice == 1){
        showCommands();
        initialiseBoard(board);
        displayBoard(board, NULL);
        printf("load <g>\n");
        printf("quit\n\n");
        playGame();
    }

   if (choice == 2){   
       showStudentInformation();
   }

   if (choice == 3){   
       printf("Good Bye!\n\n");
   }
   else showMenu();  // Recursive call
}

尝试

void showMenu(){
    Cell board[BOARD_HEIGHT][BOARD_WIDTH];

    while(1) {   // Loop until choice is 3

        int choice = validateNumber();
        if(choice == 1){
            showCommands();
            initialiseBoard(board);
            displayBoard(board, NULL);
            printf("load <g>\n");
            printf("quit\n\n");
            playGame();
        }

       else if (choice == 2){   
           showStudentInformation();
       }

       else if (choice == 3){   
           printf("Good Bye!\n\n");

           return;   // End the function
       }
   }
}

同样的想法应该应用于 PlayGame 函数以消除递归调用。也不要从 PlayGame 调用 ShowMenu - 只需执行 return