union(int i, short s, char c) un; 
un.i = 3; 
printf(“i=%d”,un.i); 
printf(“l(fā)ength = %d\n”,sizeof(un);//==4，有最大的變量來(lái)決定

void swap(int *p , int *q){ 
int temp = *p; 
*p = *q; 
*q = temp; 
}

int i = 2; 
printf(“%#x”,&i);

int arr[] = {1,2,3,4}; 
int *p = &arr; 
prinft(“%d\n”, *(p+0)); 
prinft(“%d\n”, *(p+1));