c - *日期 = "Sunday"; vs int *数字= 7；

Question

我有这样一段代码:

#include <stdio.h>
int main(void)
{
    char *date = "Sunday";
    //int *number = 7;

    printf("Today is %s, the 7 days of this week", date);
}

它按预期工作并打印

$ ./a.out
Today is Sunday, the 7 days of this week

尽管如此，当我取消评论时

#include <stdio.h>
int main(void)
{
    char *date = "Sunday";
    int *number = 7;

    printf("Today is %s, the %d days of this week", date, *number);
}

报错:

$ cc draft.c
draft.c:5:10: warning: incompatible integer to pointer conversion initializing 'int *' with an expression of type
      'int' [-Wint-conversion]
    int *number = 7;
         ^        ~
1 warning generated.

我的代码有什么问题？

Answer 1

应该是

int number = 7;
printf("Today is %s, the %d days of this week", date, number);

代替

int *number = 7;
printf("Today is %s, the %d days of this week", date, *number);

在第一个片段中，一个整型变量被初始化为 7 并且它的值被打印出来。在第二个片段中，一个指针用地址 7 初始化，然后打印内存地址 7 处的整数值。