23warning:赋值使得整数指针没有强制转换

Question

我是编程c的新手,带有数组和文件.我只是试图运行以下代码,但我得到这样的警告:

23 44警告:赋值时将整数指针,未作铸

53错误:'char'之前的预期表达式

有帮助吗？这可能是愚蠢的...但我找不到什么是错的.

#include <stdio.h>

FILE *fp;
FILE *cw;
char filename_game[40],filename_words[40];

int main()
{
    while(1)
    {
         /* Input filenames. */
            printf("\n Enter the name of the file  \n");
            gets(filename_game);
            printf("\n Give the name of the file2 \n");
            gets(filename_words);

         /* Try to open the file with the game */
            fp=fopen(/* args omitted */);                             //line23**
            if   (fp!= NULL)     
            {  
                printf("\n Successful opening %s \n",filename_game); 
                fclose(fp);
                puts("\n Enter x to exit,any other to continue! \n ");
                if ( (getc(stdin))=='x')
                   break;
                else
                    continue;
            }
            else
            {
                fprintf(stderr,"ERROR!%s \n",filename_game);
                puts("\n Enter x to exit,any other to continue! \n");
                if (getc(stdin)=='x')
                   break;
                else
                    continue;
            }

              /* Try to open the file with the names. */            //line 44**
              cw=fopen(/* args omitted */);
             if   ( cw!=NULL )   
            {  
                printf("\n Successful opening %s \n",filename_words); 
                fclose(cw);
                puts("\n Enter x to exit,any other to continue \n ");
                if ( (getc(stdin))=='x')                         
                   break;                                          //line 53**
                else
                continue;
            }
            else
            {
                fprintf(stderr,"ERROR!%s \n",filename_words);
                puts("\n Enter x to exit,any other to continue! \n");
                if (getc(stdin)=='x')
                   break;
                else
                    continue;
            }
    }   
    return 0;
}

Answer 1

你在这里缺少括号:

if (fp=fopen("crypt.txt","r")!=NULL)

该!=运营商的优先级高于=所以编译器看到这样的表达:

if ( fp = ( fopen("crypt.txt","r") != NULL ) )

fp得到1或0取决于是否fopen返回NULL.fp是一个指针,0/1是一个整数,因此警告.

你要

if ( ( fp=fopen("crypt.txt","r") ) != NULL )