继续得到预期'const char *'

时间：2015-11-16 04:36:39

标签： c

我是大学一年级学生，所以我对c不太了解。 我们有一个关于使用数组制作飞机座位的任务，我的代码继续说预期'const char *'但是参数是'char'类型并且传递'strcmp'的参数1使得指针来自整数而没有特别强调第92：2行94：2 96：2 ....直到107：2，然后是155：2到178：2。

#include <stdio.h>
#include <string.h>

char first_class();
void business_class();

int main()

{

int row,class = 0;

char X;


char seating[13][6] ={ 
{X, X, '*', '*', '*', '*'},{'*','*',X,X,'*','*'},{X,X,X,'*','*',X},{'*','*','*',X,X,'*'},{X,X,X,X,X,X},{'*','*',X,X,'*','*'},{'*',X,'*','*',X,X},{'*','*','*','*','*','*'},{X,'*','*','*',X,'*'},{X,X,X,'*','*','*'},{X,X,X,X,X,X},{'*','*','*','*','*','*'},{'*',X,X,X,'*','*'} };

int i,j;
int a;

char c;
char seat;





printf("*********************************************************\n");

printf("****   Thank you for choosing Ricardio's Airline.    ****\n");

printf("**  Best seats available for your flight, guaranteed,  **\n");

printf("****            Refund is not available              ****\n");

printf("*********************************************************\n");



printf("We have the best seats in da haus yo!\n");

printf("Please select a Class\n");

printf("1 = First Class, 2 = Business Class, 3 = Economy Class\n:");

scanf("%d", &class);


for(c='A'; c<='G'; ++c)

    printf("\t %c", c);
printf("\n");
for(i = 0;i < 14; i++)

{

    printf("Row %d", i);

    for(j = 0; j < 7; j++)
    {
    printf("\t seating[i][j]");

    if (j % 6 == 0)

    printf("\n");

}
}

if (class == 1)

first_class();        



else if (class == 2)

business_class();



else if (class == 3)

printf ("economy_class()");



else

printf("Invalid Class");     
if(strcmp(seat, "1C") == 0)
    seating[0][2] = X;
if(strcmp(seat, "1D") == 0)
    seating[0][3] = X;
if(strcmp(seat, "1E") == 0)
    seating[0][4] = X;
if(strcmp(seat, "1F") == 0)
    seating[0][5] = X;

if(strcmp(seat, "2A") == 0)
    seating[1][0] = X;
if(strcmp(seat, "2B") == 0)
    seating[1][1] = X;
if(strcmp(seat, "2E") == 0)
    seating[1][4] = X;
if(strcmp(seat, "2F") == 0)
    seating[1][5] = X;

for(c='A'; c<='G'; ++c)

    printf("\t %c", c);
printf("\n");
for(i = 0;i < 14; i++)

{

    printf("Row %d", i);

    for(j = a; j < 7; j++){

    printf("\t seating[i][j]");

    if (j % 6 == 0)

    printf("\n");
}
}

return 0;
}       


char first_class()
{

int row = 0;
char column;
char seat;        

printf ("*******************************************************\n");

printf ("*                      First Class                    *\n");

printf ("*******************************************************\n");



printf ("Rows 1 and 2 are reserved for First Class seating.\n");

printf ("Which seat would you like?\n");

scanf("%s", seat);

if(strcmp(seat, "1A") == 0)
    printf("The seat you have chosen is already taken");
if(strcmp(seat, "1B") == 0)
    printf("The seat you have chosen is already taken");
if(strcmp(seat, "1C") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "1D") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "1E") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "1F") == 0)
    printf("You have chosen seat %d %c", row,column);

if(strcmp(seat, "2A") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "2B") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "2C") == 0)
    printf("The seat you have chosen is already taken");
if(strcmp(seat, "2D") == 0)
    printf("The seat you have chosen is already taken");
if(strcmp(seat, "2E") == 0)
    printf("You have chosen seat %d %c", row,column);
if(strcmp(seat, "2F") == 0)
    printf("You have chosen seat %d %c", row,column);

else

printf("Invalid Row or That Row Is For The Other Classes");
return seat;
}
void business_class()

{
int column;
int row = 0;

printf ("*******************************************************\n");

printf ("*                   Business Class                    *\n");

printf ("*******************************************************\n");



printf ("Rows 3,4,5,7 and 8 are reserved for First Class seating.\n");

printf ("Which row would you like?\n");

scanf("%d", row);

if(row = 3)

printf("Please select your coloumn\n");

scanf("%s",column);

    if(column = 'A')
    printf("Hi");

if(row = 4)

printf("Please select your coloumn\n");

else

printf("Invalid Row or That Row Is For The Other Classes");
}

2 个答案:

答案 0 :(得分：2)

您的脚本中存在一些问题。 Firt，你必须改变第139行

char seat;

以下内容：

char *seat;

因为你像字符串一样处理变量席位，所以char就是一个字符。其他观察结果是您需要使用scanf传递变量的方向，因此，您必须替换以下行：

scanf("%s",column);
scanf("%d",row);

通过

scanf("%d",&column);
scanf("%d",&row);

请注意，在第二步中，您必须将变量的类型更改为'％d'（整数）。另一方面，你有一个函数first_class返回一个char，但是，你想要返回一个字符串的变量席位，因此，你必须通过

替换函数定义 
char* first_class()

另外，要比较变量，必须使用operator ==，请参阅函数business_class。你的最终代码必须是：

#include <stdio.h>
#include <string.h>

char *first_class();
void business_class();

int main()
{

  int row,class = 0;
  char X;
  char seating[13][6] ={ 
  {X, X, '*', '*', '*', '*'},{'*','*',X,X,'*','*'},{X,X,X,'*','*',X},{'*','*','*',X,X,'*'},{X,X,X,X,X,X},{'*','*',X,X,'*','*'},{'*',X,'*','*',X,X},{'*','*','*','*','*','*'},{X,'*','*','*',X,'*'},{X,X,X,'*','*','*'},{X,X,X,X,X,X},{'*','*','*','*','*','*'},{'*',X,X,X,'*','*'} };

  int i,j;
  int a;

  char c;
  char *seat;
  seat = (char *) malloc(15); 




  printf("*********************************************************\n");

  printf("****   Thank you for choosing Ricardio's Airline.    ****\n");

  printf("**  Best seats available for your flight, guaranteed,  **\n");

  printf("****            Refund is not available              ****\n");

  printf("*********************************************************\n");



  printf("We have the best seats in da haus yo!\n");

  printf("Please select a Class\n");

  printf("1 = First Class, 2 = Business Class, 3 = Economy Class\n:");

  scanf("%d", &class);


  for(c='A'; c<='G'; ++c)
      printf("\t %c", c);
  printf("\n");

  for(i = 0;i < 14; i++)
  {
      printf("Row %d", i);
      for(j = 0; j < 7; j++)
      {
        printf("\t seating[i][j]");
        if (j % 6 == 0)
           printf("\n");
      }
  }

  if (class == 1)
    first_class();        
  else if (class == 2)
    business_class();
  else if (class == 3)
    printf ("economy_class()");
  else
    printf("Invalid Class");     


  if(strcmp(seat, "1C") == 0)
      seating[0][2] = X;
  if(strcmp(seat, "1D") == 0)
      seating[0][3] = X;
  if(strcmp(seat, "1E") == 0)
      seating[0][4] = X;
  if(strcmp(seat, "1F") == 0)
      seating[0][5] = X;

  if(strcmp(seat, "2A") == 0)
      seating[1][0] = X;
  if(strcmp(seat, "2B") == 0)
      seating[1][1] = X;
  if(strcmp(seat, "2E") == 0)
      seating[1][4] = X;
  if(strcmp(seat, "2F") == 0)
      seating[1][5] = X;

  for(c='A'; c<='G'; ++c)
      printf("\t %c", c);
  printf("\n");

  for(i = 0;i < 14; i++)
  {
      printf("Row %d", i);
      for(j = a; j < 7; j++){
        printf("\t seating[i][j]");
        if (j % 6 == 0)
           printf("\n");
      }
  }

  return 0;
}       


char* first_class()
{

  int row = 0;
  char column;
  char *seat;  

  printf ("*******************************************************\n");

  printf ("*                      First Class                    *\n");

  printf ("*******************************************************\n");



  printf ("Rows 1 and 2 are reserved for First Class seating.\n");

  printf ("Which seat would you like?\n");

  scanf("%s", seat);


  if(strcmp(seat, "1A") == 0)
      printf("The seat you have chosen is already taken");
  if(strcmp(seat, "1B") == 0)
      printf("The seat you have chosen is already taken");
  if(strcmp(seat, "1C") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "1D") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "1E") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "1F") == 0)
      printf("You have chosen seat %d %c", row,column);

  if(strcmp(seat, "2A") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "2B") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "2C") == 0)
      printf("The seat you have chosen is already taken");
  if(strcmp(seat, "2D") == 0)
      printf("The seat you have chosen is already taken");
  if(strcmp(seat, "2E") == 0)
      printf("You have chosen seat %d %c", row,column);
  if(strcmp(seat, "2F") == 0)
      printf("You have chosen seat %d %c", row,column);

  else

  printf("Invalid Row or That Row Is For The Other Classes");
  return seat;
}




void business_class()
{
  int column;
  int row = 0;

  printf ("*******************************************************\n");
  printf ("*                   Business Class                    *\n");
  printf ("*******************************************************\n");
  printf ("Rows 3,4,5,7 and 8 are reserved for First Class seating.\n");
  printf ("Which row would you like?\n");
  scanf("%d", &row);

  if(row == 3)
      printf("Please select your coloumn\n");
  scanf("%d",&column);

  if(column == 'A')
      printf("Hi");

  if(row == 4)
      printf("Please select your coloumn\n");
  else
      printf("Invalid Row or That Row Is For The Other Classes");
}

答案 1 :(得分：0)

关于这种界限：

if(strcmp(seat, "1C") == 0)

seat is a single character and“1C”`是一个字符串（包括尾随的NUL字符）是3个字节。

因此单个字符不能与字符串进行比较。

另外，这种行：

scanf("%s", seat);

表示将字符串读入单个char变量seat。

如果用户输入超出<newline>的任何内容，缓冲区将会溢出！

（scanf（）在读取字符串时总是附加NUL字符）

缓冲区溢出是未定义的行为，可能/将导致seg故障事件。

建议将变量seat声明为

char seat[5];

并修改对scanf()的调用以将最大字符数输入限制为小于座位长度[1]的1。 

scanf( '%4s", seat);

请通过附加更正代码的编辑更正代码中的所有此类问题。

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