1.定义:
union(int i, short s, char c) un;
un.i = 3;
printf(“i=%d”,un.i);
printf(“length = %d\n”,sizeof(un);//==4,有最大的变量来决定
2.相当与java里的List T类型
3.数据交换
void swap(int *p , int *q){
int temp = *p;
*p = *q;
*q = temp;
}
4、打印地址
int i = 2;
printf(“%#x”,&i);
5.指针打印数组值
int arr[] = {1,2,3,4};
int *p = &arr;
prinft(“%d\n”, *(p+0));
prinft(“%d\n”, *(p+1));