22-结构体的一些用法

ゞ浴缸里的玫瑰 2022-12-21 15:52 77阅读 0赞

> 类型设计完成后,其作用和基本类型作用一样  
> struct 类型名 变量名;  
> 结构体的普通变量通过".“访问其成员  
> struct 类型名 \*指针变量名;  
> 结构体的指针变量通过”->"访问其成员  
> 结构体作为参数传递时,总是传指针,不传结构体本身  
> typedef 旧类型 新类型;  
> 1.起别名,简写  
> 2.和问题类型相关这里是引用

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <time.h>
    
    typedef unsigned long long int uint64;
    typedef int * Pint;
    typedef int Arr[10];
    struct A
    {
        
    	char a;
    	int b;
    };
    
    typedef struct A A;
    typedef struct B
    {
        
    	char a;
    	int b;
    }B;
    
    int main()
    {
        
    	unsigned long long int a = 10;
    	uint64 b = 20;
    	int d = 100;
    	Pint c = &d;
    	Arr e;//int数组
    	A sa;
    	time_t t1 = time(NULL);
    	size_t;
    	malloc();
    	printf("%d\n",sizeof(e));//
    	return 0;
    }
    struct A
    {
        
    	char a;
    	int b;
    };
    
    int main()
    {
        
    	struct A sa;
    	//A sc;//c++可以
    	unsigned long long a = 10;
    
    	return 0;
    }
    
    struct D
    {
        
    	char a;
    	int a;//error
    };
    
    //输出Student的信息
    //void Show(struct Student stu)//传参 ,不好,浪费空间
    void Show(struct Student *p)
    {
        
    	printf("%s,%d\n",p->name,p->age);
    }
    
    //输出Student数组的内容
    void Show(struct Student *arr,int len)
    {
        
    	//for(int i=0;i<sizeof(arr)/sizeof(arr[0]);i++)//error
    	for(int i=0;i<len;i++)
    	{
        
    		printf("%s,%d\n",arr[i].name,arr[i].age);
    	}
    }
    
    int main()
    {
        
    	struct Student stu1 = {
        "liubei",23};
    	Show(&stu1);
    	struct Student arr[3] = {
        "caocao",20,"liubei",21,"sunquan",18};
    	arr[1].age = 23;
    	//输出arr的所有内容
    	for(int i=0;i<sizeof(arr)/sizeof(arr[0]);i++)
    	{
        
    		printf("%s,%d\n",arr[i].name,arr[i].age);
    	}
    	Show(arr,sizeof(arr)/sizeof(arr[0]));
    	
    	return 0;
    }
    
    int main()
    {
        
    	struct Student stu1;
    	strcpy(stu1.name,"刘备");
    
    	struct Student *ps = &stu1;
    	ps->age = 23;
    	
    	return 0;
    }
    struct Student//设计学生结构体
    {
        
    	char name[20];
    	int age;
    };//类型设计完成
    
    //结构体指针
    int main()
    {
        
    	int a = 10;
    	int *p = &a;
    
    	struct Student stu1 = {
        "sunquan",18};
    	struct Student *p1 = &stu1;//定义结构体指针
    	//通过p1将年龄改为19
    	p1->age = 19;//(*p1).age = 19;
    	//通过p1将姓名改为"张飞"
    	strcpy(p1->name,"张飞");
    	printf("%s,%d\n",p1->name,p1->age);
    	return 0;
    }
    
    //结构体普通变量
    int main()
    {
        
    	int a = 10;
    	int b;
    	int arr[10];
    	int *p = &a;
    	struct Student stu1;//随机值
    	struct Student stu2 = {
        "liubei",20};
    	stu2.age = 23;
    	//stu1  改为"曹操",24
    	//stu1.name = "caocao";
    	strcpy(stu1.name,"曹操");
    	stu1.age = 24;
    	//输出stu1的信息
    	printf("%s,%d\n",stu1.name,stu1.age);
    	return 0;
    }