#include<stdio.h>
#include<stdlib.h>struct info{char c;        //1    2    4    8    double num;    //1    2    4    8        char short int doublechar ch[9];    //9    10    12    16

};void main() {printf("%d\n",sizeof(struct info));struct info in={'a',5.2,"hello"};printf("%p\n",&in);printf("%p\n",&in.c);printf("%p\n",&in.num);printf("%p\n",&in.ch);system("pause");
}

#include<stdio.h>
#include<stdlib.h>//枚举的一般形式，限定在这个范围内取值
//如果没有一个赋初值，就会从0循环到最后一个，每次加1
//如果第一个赋初值，后面每个加1
//除非自己赋值，否则计算机赋值会让每个枚举常量都不同
enum level{司令=5,军长=5,师长,旅长,团长,营长,连长,排长,班长,士兵
};void main() {enum level l1=司令;enum level l2=军长;enum level l3=师长;printf("%d\n",l1);printf("%d\n",l2);printf("%d\n",l3);system("pause");
}

#include<stdio.h>
#include<stdlib.h>typedef int aa;            //typedef没有创建数据类型，给已经有的数据类型起一个别名.编译时处理，仅适用于类型
#define zhengshu num    //define是替换，预处理，适用于任何场合void main() {aa zhengshu=10;printf("%d\n",num);system("pause");
}

#include<stdio.h>
#include<stdlib.h>typedef int I;//给int一个别称
typedef int* IP;
void main() {I num=100;//int num=100IP p=&num;//int *p=&numprintf("%d,%d\n",num,*p);printf("%p,%p\n",&num,p);system("pause");
}

#include<stdio.h>
#include<stdlib.h>void main() {/*int a[10];int s[10];*/typedef int s[10];//重定义数组类型
    s x;for (int i = 0; i < 10; i++){x[i]=i;printf("%d\n",x[i]);}system("pause");
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>struct info{char name[100];int num;
};typedef struct info I;//I=struct info
typedef struct info* P;//P=struct info*void main() {I s;strcpy(s.name,"yincheng");s.num=100;printf("%s,%d\n",s.name,s.num);P ip=(P)malloc(sizeof(I));strcpy(ip->name,"yincheng8848");ip->num=8888;printf("%s,%d\n",(*ip).name,ip->num);　　free(ip);system("pause");
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>typedef struct tel{char name[30];long long num;
}T,*P;void main() {printf("%d\n",sizeof(struct tel));printf("%d\n",sizeof(T));printf("%d\n",sizeof(P));T t1;strcpy(t1.name,"yincheng");t1.num=18288889999;printf("%s,%lld\n",t1.name,t1.num);P pt1=(P)malloc(sizeof(T));//malloc之后记得要freestrcpy(pt1->name,"尹成");pt1->num=18611118888;printf("%s,%d\n",(*pt1).name,pt1->num);free(pt1);system("pause");
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>typedef struct string{char *p;int len;
}S;//浅拷贝，共享内存
void main1() {S s1,s2;s1.len=10;s1.p=(char *)malloc(sizeof(char)*10);strcpy(s1.p,"hello");printf("s1.p=%s\n",s1.p);s2.len=s1.len;s2.p=s1.p;*(s1.p)='K';printf("s2.p=%s\n",s2.p);system("pause");
}
//深拷贝，拷贝内存内容
void main() {S s1,s2;s1.len=10;s1.p=(char *)malloc(sizeof(char)*10);strcpy(s1.p,"hello");printf("s1.p=%s\n",s1.p);s2.len=s1.len;s2.p=(char *)malloc(sizeof(char)*10);strcpy(s2.p,s1.p);*(s1.p)='K';printf("s2.p=%s\n",s2.p);system("pause");
}