C语言基础学习：结构体与结构体指针

• 结构体定义与使用
• 结构体指针与动态内存开辟
• 结构体数组
• 结构体与结构体指针取别名

//java/kotlin有类的概念，C语言 函数 结构体（相当于java中的类）
struct Dog{
	//成员
	char name[10];
	int age;
	char sex;
};//必须给写；

int main（）{
	struct Dog dog;//当前这行代码写完，没有初始化的时候，成员默认值是系统值
	//赋值操作
	//dog.name = "旺财";这是java的写法，在c中必须使用copy的api
	strcpy(dog.name,"旺财");
	dog.age = 3;
	dag.sex = 'G';
	printf("name:%s,age:%d,sex:%c n",dog,name,dog.age,dog.sex);

	return 0;
}

//第二种
struct Person{
	//成员
	char * name;
	int age;
	char sex;
}ppp = {"abc",33,'M'}
ppp2,
ppp3,
ppp4
;//必须给写；

int main（）{
	// Person == ppp == struct Person ppp;
	printf("name:%s,age:%d,sex:%c n",ppp ,name,ppp.age,ppp.sex);
	//赋值
	//  strcpy(ppp4.name,"aaa");会失败，因为定义的是指针
	ppp3.name = "adcd";
	ppp4.age = 3;
	ppp4.sex = 'G';
	printf("name:%s,age:%d,sex:%cn",ppp4,name,ppp4.age,ppp4.sex);
	return 0;
}

//第三种
struct Sutdy{
	char * studyContext;
};

struct Student{
	char name[10];
	int age;
	char sex;
	struct StUDY STUDY;
	struct Wan{
		char * wanContext;
	} wan;

};

int main（）{
	struct Student student = {"李元霸",88，'m'，
		{"学习c"}，
		{"王者荣耀"}
	};
	printf("name:%s,age:%d,sex:%c,study:%s,wan:%s n",student,name,
		student.age,student.sex,student.sudyu.studyConent,student.wan.wanContent);
	return 0;
}

struct Cat{
	char name[10];
	int age;
};

int main(){ //栈
	// 结构体
	struct Cat cat = {"小花猫"，2};
	//结构体指针 -> 调用一级指针成员
	struct Cat * carp = &cat;
	catp->age = 3;
	strcpy(catp->name,"小花猫2");
	printf("name:%s,age:%d n",catp->name,catp->age);//输出name：小花猫2，age：3
	return 0;
}

struct Cat{
	char name[10];
	int age;
};

int main(){ //堆
	struct Cat * cat = malloc(sizeof(strcut Cat));
	strcpy(cat->name,"金色猫");
	cat->age = 5;
	
	printf("name:%s,age:%d n",cat->name,cat->age);//输出name：金色猫，age：5
	if(cat){
		free(cat);
		cat = NULL;
	}
	return 0;
}

struct Cat{
	char name[10];
	int age;
};

int main(){ 
	strcut Cat cat[10]={
		{"abcd",1}
		{}
		{}
		{} 
		{}
		{}
		{}
		{}
		{}
		{}
	};
	struct Cat cat9 = {"小花猫9",9};
	cat[9] = cat9;// *（cat + 9） = cat9;
	printf("name:%s,age:%d n",cat9->name,cat9->age);
	
	//堆区 动态范畴
	struct Cat * cat2 = malloc(sizeof (struct cat) * 10);
	// 如果现在立刻给cat2赋值，是哪个元素呢？ 默认指向首元素
	strcpy(cat2->name,"adfa");
	cat2.age = 1;
	printf("name:%s,age:%d n",cat2->name,cat2->age);
	//给第8个元素复制
	cat2+=7;
	strcpy(cat2->name,"adfa");
	cat2.age = 1;
	printf("name:%s,age:%d n",cat2->name,cat2->age);
	return 0;
}

struct Workder_{
	char name[10];
	int age;
	char sex;
};
//一定要加typedef，别名跟结构体名字一样，是为了兼容,
typedef struct Workder_;
typedef Workder_ * workder;
//还可以这样,定义结构体跟取别名一气呵成
typedef struct{
	char name[10];
	int age;
	char sex;
} AV;

// 枚举 int 类型

enum CommentType {
	TEXT = 10,
	TEXT_IMAGE,
	IMAGE
};

int main(){
	//这里就不要struct了
	Workder worker = malloc(sizeof(workder_));
	//以前是
	struct Workder_ workder1 = malloc(sizeof (struct Workder_));
	//现在
	Workder_ workder2 = malloc(sizeof (Workder_));
	AV av = {};
	AV * avp = malloc(sizeof (AV));
	// Clion写法
	enum CommentType commentType = TEXT;
	//vs
	CommentType commentType = TEXT;

	return 0;
}