结构类型

结构体
定义有三种：

#include <stdio.h>struct date {    int year;    int month;    int day;};//struct date today;/*//  definition of structure method 2struct {    int year;    int month;    int day;}today;*//*//   definition of structure method 3struct date{    int year;    int month;    int day;}today;*/int main(int argc, const char *argv[]) {    struct date tomorrow =  {2015, 5, 13};    struct date today = {.year = 2015, .day = 12};  // Note: first defination and initialization can be work//   today = {.year = 2015, .day = 12};         // it didn't work //   today = tomorrow;          // array can't be assignment each other    today.month = 5;    printf("Date of tomorrow: %d-%d-%d\n", tomorrow.year, tomorrow.month, tomorrow.day);    printf("Date of today: %d-%d-%d\n", today.year, today.month, today.day);        struct date *thisDay = NULL;    thisDay = &today;    thisDay->day++;    thisDay->year++;    thisDay->month++;     printf("*thisDay: %d--%d--%d\n ", thisDay->day, thisDay->month, thisDay->year);    return 0;}

结构，又名结构体，在其结构中可以定义多种不同数据类型的变量，
数组呢，只能定义相同数据类型的变量，一经定义后，不可改变；数组名亦是地址，但结构名不是；结构在作函数参数时要借用相关结构指针操作；

#include <stdio.h>struct point {    int x;    int y;};void swap(int a[], int i);void setPoint(struct point *p1);int main(){    int a[] = {3, 12,54 , 5, 6};    struct point *p = NULL;    struct point mypoint = {2, 5};    p = &mypoint;    setPoint(p);----------------        //  ....... many codes loss    return 0;}