通俗易懂C语言--结构体

结构体定义

第一种形式

struct 结构体类型名
{
成员表列
}；

struct TIME
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
};

怎么使用：

#include <stdio.h>

struct TIME
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
};

int main() {
    struct TIME time;
	time.year=2021;
    printf("%d\n",time.year);
    return 0;
}

第二种形式

struct TIME
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}time;

 怎么使用：

#include <stdio.h>

struct TIME
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}time;

int main() {
   
	time.year=2021;
    printf("%d\n",time.year);
    return 0;
}

第三种形式

typedef struct 
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

typedef struct _TIME
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

怎么使用：

#include <stdio.h>

typedef struct 
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

int main() {
    TIME time;
	time.year=2021;
    printf("%d\n",time.year);
    return 0;
}

有了结构体，咱们可以先给它初始化

结构体初始化

常规初始化

#include <stdio.h>

typedef struct 
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

int main() {
    TIME time;
	time.year=2021;//常规初始化
    time.date=1;//常规初始化
    printf("%d\n",time.year);
    return 0;
}

顺序初始化

#include <stdio.h>

typedef struct 
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

int main() {
    TIME time={1,3,2021,5,16,59};//顺序初始化
    printf("%d\n",time.year);
    return 0;
}

乱序初始化

#include <stdio.h>

typedef struct 
{
        int date;
        int month;
        int year;
        int hour;
        int min;
        int sec;
}TIME;

int main() {
    TIME time={
     .sec=59，
     .min=21，
     .year=2021，
     .month=4，
     .date=2，
     .hour=3，
};//乱序初始化
    printf("%d\n",time.year);
    return 0;
}

乱序初始化有个问题，编译器太旧了会报错，所以VC++这种是不能编译通过的

结构体数组

struct TIME
{
        int date;
        int month;
        int year;
};

struct TIME time[]={
//date,month,year
{1,2,2021},
{2,3,2021},
{3,4,2021},
{4,5,2021},
{5,6,2021},
{6,7,2021},
};

怎么使用：

struct TIME
{
        int date;
        int month;
        int year;
};

struct TIME time[]={
//date,month,year
{1,2,2021},
{2,3,2021},
{3,4,2021},
{4,5,2021},
{5,6,2021},
{6,7,2021},
};

int main() {

	
    printf("%d %d %d \n",time[1].date,time[1].month,time[1].year);
    return 0;
}

结构体指针

struct TIME
{
        int date;
        int month;
        int year;
};

struct TIME time={1,2,2021};

int main() {
    struct TIME *p;
    p=&time;
    printf("%d %d %d \n",p->date,p->month,p->year);
    return 0;
}

 ->这个符号只有在结构体指针中使用，下一节再接着讲