某32位系统下, C++程序，请计算sizeof 的值
char str[] = "http://www.xxxxx.com" ;
char *p = str ;
int n = 10;
请计算
sizeof (str ) = 1
sizeof ( p ) = 2
sizeof ( n ) = 3
}
void *p = malloc( 100 ); 请计算 sizeof ( p ) = 5