c - scanf 和 char 变量问题

Question

好吧，我正在阅读C for dummies，但我又遇到了scanf 问题。我早些时候写了另一个提问者有类似的问题，但修复在这里不起作用。每次编译，gcc 总是说:

MADLIB1.C: In function ‘int main()’:
MADLIB1.C:19:27: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char ()[20]’ [-Wformat]
MADLIB1.C:21:22: warning: format ‘%s’ expects argument of type ‘char’, but argument 2 has type ‘char ()[20]’ [-Wformat]
MADLIB1.C:23:23: warning: format ‘%s’ expects argument of type ‘char’, but argument 2 has type ‘char ()[20]’ [-Wformat]
MADLIB1.C:25:27: warning: format ‘%s’ expects argument of type ‘char’, but argument 2 has type ‘char (*)[20]’ [-Wformat]
MADLIB1.C:31:52: error: expected ‘}’ at end of input

这是我的代码:

/*
MADLIBI.C Source Code
Written by Arshad Husain
*/

#include <stdio.h>

int main()
{

    char adjective[20];
    char food[20];
    char chore[20];
    char furniture[20];

    /* Get the words to use in the madlib */

    printf("Enter an adjective");     /* prompt */
    scanf("%s",&adjective);
    printf("Enter a food");
    scanf("%s",&food);
    printf("Enter a household chore (past tense):");
    scanf("%s",&chore);
    printf("Enter an item of furniture");
    scanf("%s",&furniture);

    /* Display the output */

    printf("\n\nDon't touch that %s %s!\n", adjective, food);
    printf("I just %s the %s!\n", chore, furniture);

    return(0);
}

Answer 1

你不应该对数组使用 address-of，它们已经是指针了:

printf("Enter an adjective");     /* prompt */
scanf("%s",adjective);

当你使用 address-of, e.i., & 时，它变成了 char **，这不是 scanf 所期望的。

另外，对于这个例子，这样做更安全:

scanf("%19s",adjective); /* maximum 19 chars */

防止溢出。