c - 我想创建一个程序来使用 C 中的字符串函数比较两个字符串。我的代码有什么问题？我是 C 的初学者

Question

#include<stdio.h>
#include<curses.h>
#include<string.h>
void main()
{   const char *str1[20];
    const char *str2[20];
    int comp;
    printf("Enter the first string:\n");
    scanf("%s",&str1);
    printf("Enter the second string:\n");
    scanf("%s",&str2);
    comp=strcmp(str1,str2);
}

这是在 gcc 编译器 4.8 中编译的。详细的解释将不胜感激。

错误信息:

strcmp.c: In function ‘main’:
strcmp.c:10:10: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘const char * (*)[20]’ [-Wformat=]
  scanf("%s",&str1);
          ^
strcmp.c:12:10: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘const char * (*)[20]’ [-Wformat=]
  scanf("%s",&str2);
          ^
strcmp.c:13:14: warning: passing argument 1 of ‘strcmp’ from incompatible pointer type [-Wincompatible-pointer-types]
  comp=strcmp(str1,str2);
              ^~~~
In file included from strcmp.c:3:0:
/usr/include/string.h:140:12: note: expected ‘const char *’ but argument is of type ‘const char **’
 extern int strcmp (const char *__s1, const char *__s2)
            ^~~~~~
strcmp.c:13:19: warning: passing argument 2 of ‘strcmp’ from incompatible pointer type [-Wincompatible-pointer-types]
  comp=strcmp(str1,str2);
                   ^~~~
In file included from strcmp.c:3:0:
/usr/include/string.h:140:12: note: expected ‘const char *’ but argument is of type ‘const char **’
 extern int strcmp (const char *__s1, const char *__s2)

Answer 1

const char *str1[20];

应该是

char str1[20];

你想要一个可变的字符数组，而不是一个指针数组。

scanf("%s",&str1);

应该是:

scanf("%s",str1);

scanf 函数需要地址来存储输入。这等同于 &str1[0]，它是 str1 衰减成的。