c一7自定义数据类型

第7章自定义数据类型2课时面向对象程序设计1本章内容7.1结构体类型7.2枚举类型27.1结构体类型3structStudent{intnum;stringname;charsex;intage;floatscore;stringaddress;};与数组不同,结构体中各元素可以是不同类型

.类型定义Studentstudent1={10001,"ZhangXin",'M',19,90.5,"Shanghai"};变量定义和初始化结构体变量的另外两种定义形式4structStudent{intnum;stringname;charsex;intage;floatscore;stringaddress;}student1,student2;struct{intnum;stringname;charsex;intage;floatscore;stringaddress;}student1,student2;形式二形式三成员也可以是一个结构体5structDate//声明一个结构体类型Date{intmonth;intday;intyear;};structStudent//声明一个结构体类型Student{intnum;charname[20];charsex;intage;Datebirthday;//Date是结构体类型,birthday是Date类型的成员charaddr[30];}student1,student2;//定义student1和student2为结构体类型Student的变量引用结构体变量6Students1,s2,s3;s1=s2;s1.num=10010;//可单独赋值s3.score=s1.score+s2.score;cout<<s1.num;cout<<&s1;//s1的首地址cout<<&s1.age;正确Students1,s2,s3;//不能作为整体赋值s1={10001,"ZhangXin",'M',19,90.5,"Shanghai"};//不能作为整体运算、输入输出s1=s2+s3;cout<<s1;错误例7.1引用结构体变量成员7#include<iostream>#include<iomanip>#include<string>usingnamespacestd;structStudent{intID;stringname;stringsex;floatscore;};intmain(){Studentstudent1,student2={10002,“张三","女",89.5};student1=student2;cout<<"学号姓名性别成绩"<<endl;cout<<setw(6)<<student1.ID;cout<<setw(8)<<;cout<<setw(6)<<student1.sex;cout<<setw(6)<<student1.score<<endl;return0;}定义结构体数组8Studentstu[3];//定义Student类型的数组stustructStudent{…}stu[3];struct{…}stu[3];形式一形式二形式三结构体数组初始化9Studentstu[]={{10101,"LiLin",'M',18,87.5,"103BeijingRoad"},{10102,"ZhangFun",'M',19,99,"130ShanghaiRoad"},{10104,"WangMin",'F',20,78.5,"1010ZhongshanRoad"}};数组各元素在内存中连续存放.例7.2统计候选人得票10#include<iostream>#include<string>usingnamespacestd;structPerson{stringname;intcount;};intmain(){Personleader[3]={"Li",0,"Liu",0,"Wang",0};inti,j;

cout<<"候选人分别是Li,Liu和Wang,共有张选票"<<endl<<endl;stringleader_name;for(i=0;i<10;i++)

{cout<<"请输入第"<<i+1<<"张选票上候选人的姓:";cin>>leader_name;for(j=0;j<3;j++)

{if(leader_name==leader[j].name)leader[j].count++;

}

}cout<<endl;for(i=0;i<3;i++)

{cout<<leader[i].name<<":"<<leader[i].count<<endl;

}return0;}指向结构体变量的指针11#include<iostream>#include<string>usingnamespacestd;structStudent//声明结构体类型student{intnum;stringname;charsex;floatscore;};intmain(){Studentstu={10301,"WangFang",'f',89.5};Student*p=&stu;//定义p为指向Student类型数据的指针变量并指向stu

cout<<stu.num<<""<<<<""<<stu.sex<<""<<stu.score<<endl;cout<<(*p).num<<""<<(*p).name<<""<<(*p).sex<<""<<(*p).score<<endl;return0;}结构体变量运算符12结构体变量.成员名

//如stu.num(*p).成员名

//如(*p).nump->成员名

//“->”为指向运算符三种形式等价链表链表是一种数据结构“头指针”变量head存放第一个元素的地址每个中间结点包括两个部分:用户数据,下一个结点地址链表中各元素在内存中的存储单元可以是不连续的13链表的实现14structStudent{intnum;floatscore;Student*next;//next指向Student结构体变量};链表必须利用结构体变量和指针才能实现.例7.4静态链表15structStudent{intID;stringname;stringsex;floatscore;Student*pNext;};intmain(){Students1={10002,"张三","女",89.5,NULL};Students2={10102,"李四","男",99,NULL};Students3={10104,"王五","男",78.5,NULL};Student*pHead,*p;pHead=&s1;s1.pNext=&s2;s2.pNext=&s3;

cout<<"学号姓名性别成绩"<<endl;for(p=pHead;NULL!=p;p=p->pNext){cout<<setw(6)<<p->ID;cout<<setw(8)<<p->name;cout<<setw(6)<<p->sex;cout<<setw(6)<<p->score<<endl;}return0;}结构体作为函数参数161.用结构体变量名作参数//值传递2.用指向结构体变量的指针作参数3.用结构体变量的引用作参数三种方法例7.5a用结构体变量名作参数17#include<iostream>#include<string>usingnamespacestd;structStudent{intnum;stringname;floatscore[3];};voidprint(Studentstu){cout<<stu.num<<""<<<<""<<stu.score[0]<<""<<stu.score[1]<<""<<stu.score[2]<<endl;}intmain(){Studentstu;stu.num=12345;="LiFung";stu.score[0]=67.5;stu.score[1]=89;stu.score[2]=78.5;print(stu);return0;}值传递,形参单独开辟存储单元.例7.5b用指针作参数18#include<iostream>#include<string>usingnamespacestd;structStudent{intnum;stringname;floatscore[3];};voidprint(Student*p){cout<<p->num<<""<<p->name<<""<<p->score[0]<<""<<p->score[1]<<""<<p->score[2]<<endl;}intmain(){Studentstu;stu.num=12345;="LiFung";stu.score[0]=67.5;stu.score[1]=89;stu.score[2]=78.5;print(&stu);return0;}形参是结构体起始地址,占4字节.例7.5c用引用作参数19#include<iostream>#include<string>usingnamespacestd;structStudent{intnum;stringname;floatscore[3];};voidprint(Student&stu){cout<<stu.num<<""<<stu.name<<""<<stu.score[0]<<""<<stu.score[1]<<""<<stu.score[2]<<endl;}intmain(){Studentstu;stu.num=12345;="LiFung";stu.score[0]=67.5;stu.score[1]=89;stu.score[2]=78.5;print(stu);return0;}传递的是实参的地址,形参和实参是同一对象.new和delete运算符20newint;//开辟一个存放整数的存储空间,返回指向该存储空间的地址(即指针)newint(100);//开辟一个存放整数的空间,并指定该整数的初值为100,返回指向该存储空间的地址newchar[10];//开辟一个存放字符数组(包括10个元素)的空间,返回首元素的地址newint[5][4];//开辟一个存放二维整型数组(大小为5*4)的空间,返回首元素的地址float*p=newfloat(3.14159);//开辟一个存放单精度数的空间,并指定该实数的初值为3.14159,将返回的该空间的地址赋给指针变量pnew类型[初值]

//如果内存不足,new返回NULL//用new分配数组空间时不能指定初值delete[]指针变量//在指针变量前加方括号,表示是对数组空间的操作new和delete运算符new运算符例子例7.6动态分配存放结构体的空间21#include<iostream>#include<string>usingnamespacestd;structStudent{stringname;intnum;charsex;};intmain(){Student*p=NULL;p=newStudent;if(NULL!=p){p->name="WangFun";p->num=10123;p->sex='m';cout<<p->name<<endl<<p->num<<endl<<p->sex<<endl;

deletep;p=NULL;}return0;}例7.6B动态链表结构(1)22#include<iostream>usingnamespacestd;structStudent{intnum;floatscore;Student*next;};Student*CreatLink();voidListLink(Student*);voidDeleteLink(Student*);intmain(){Student*phead=CreatLink();ListLink(phead);DeleteLink(phead);return0;}Student*CreatLink()/*返回指向链表头指针*/{Student*head=NULL,*p,*tail; while(true){p=newStudent;cout<<"输入学号，以0结束：";cin>>p->num;if(!p->num)break;cout<<"输入分数：";cin>>p->score;p->next=NULL;if(head==NULL){head=p;tail=p;}else{tail->next=p;tail=p;/*指向尾结点*/}}returnhead;}例7.6B动态链表结构(2)23voidListLink(Student*phead){Student*p;cout<<endl<<"学号分数"<<endl;for(p=phead;p!=NULL;p=p->next){cout<<p->num<<""<<p->score<<endl;}}voidDelete