day15

指针变量的初始化

#include<stdio.h>	
int main(int argc, const char *argv[])
{
	//初始化指针
	int num=520;
	//num原地址
	printf("num的地址为:%#X\n",&num);
	//初始化指针为&num
	int *p=&num;
	printf("p=%#X\n",p);
	
	//********
	//指针间初始化
	int *q=p;
	printf("q=%#x\n",q);
	//return 0;
	//初始化为0
	int *k=NULL;
	printf("k=%p\n",k);
	//野指针
	int *y;
	printf("y=%p\n",y);
	
}

验证&与*互为逆运算

#include<stdio.h>	
int main(int argc, const char *argv[])
{
int num = 520;
//初始化num;
int *p=&num;
//验证&与*互为逆运算
//*&num=*p=num
printf("*&num=%d\n",*&num);//520

//&*p=&num=p

printf("&*p=%p\n",&*p);//地址


}

大小端

#include<stdio.h>
int main(int argc, const char *argv[])
{
	int num = 0x12345678;
	char value = 'A';
	int *p = &num;
	char *q = &value;
	printf("*p = %d,*q = %c\n",*p,*q);
	//判断指针大小
	printf("sizeof(p) = %ld,sizeof(q) = %ld\n",sizeof(p),sizeof(q));
	//用char进行一字节的判断
	q = (char *)p;
	printf("p = %p,q = %p,&num = %p\n",p,q,&num);
	printf("*p = %#x,*q = %#x\n",*p,*q);
	if(*q == 0x78)
		printf("此主机为小端存储\n");
	else if(*q == 0x12)
		printf("此主机为大端存储\n");
	p = p+1;
	q = q+1;
	printf("p = %p,q = %p,&num = %p\n",p,q,&num);
	printf("*p = %#x,*q = %#x\n",*p,*q);
	return 0;
}