scanf("%d", &a); &操作符得到存储用户输入值变量a的地址
#指针变量声明
int a; 指针变量声明涉及一个名为解引用操作符()的特殊操作符,用于帮助编译器识别它是一个指针变量。 关联数据类型通知编译器它持有变量的数据类型地址的类型。
#include <stdio.h>
int main(int argc, char const *argv[])
{
int num = 10;
int *ptr = #
int **mptr = &ptr;
printf("Value of var num = %d\n", num); // 10
printf("Value of var num = %d\n", *ptr); // 10
printf("Value of var num = %d\n", **mptr); //10
printf("\n");
printf("Address of var num = %p\n", &num); // 000000000061FE1C
printf("Address of var num = %p\n", ptr); // 000000000061FE1C
printf("Address of var num = %p\n", *mptr); // 000000000061FE1C
printf("\n");
printf("Address of pointer var ptr = %p\n", &ptr); // 000000000061FE10
printf("Address of pointer var ptr = %p\n", mptr); // 000000000061FE10
printf("Address of pointer var ptr = %p\n", &mptr); // 000000000061FE08
return 0;
}