C语言面试题——指针与数组

#include <stdio.h>
#include <string.h>
#define F(X,Y) (X)*(Y)

struct s{
	int x;
	int y;
}data[2]={{10,100},{20,200}};

int main(void)
{
	
	char str[][20] = {{"Hello"},{"Beijing"}};
	char *ptr = str[0];//等同于char *ptr = *str;
	printf("strlen(p+20) = %d\n",strlen(ptr+20));
        //ptr+20之后，指针ptr指向了字符串“Beijing”；
        int a = 3, b=4;
	printf("%d\n",F(a++,b++));
	struct s *p = data;
	printf("%d\n",++(p->x));
	
	return 0;
}

运行结果：

strlen(p+20) = 7
12
11