达内esd1407c笔记1C简介和编程基本变化

C+笔maruzhong/ruzhongmaCC++2.5 1.51.5I/O1天命名空间的概念和使用 简介和编程的基本变化C语言的简介1969年，使用汇编语言编写操作系统，发明了一门语言B语言，-在B语言的基础上NewB语言，后来改名为CC1972C++语言的简介在C语言的基础上,本-特(BjarneStroustrup)做了一定的扩展，起名NewC语言，后来改名C++,1983相关的历史事件 1998年，第一个ISOC++标准诞生(vc6.01998年诞生)C++0x部分编译器支持C++和C语言的比较vixxx.shdate;cal;ls-a;a=10;性//int*pimalloc(sizeof(int));1+1=2doublefloatC++的主要用途级编程的基本变化C语言中源文件：CC++xxx.hppC#include<stdio.h>C++中：#include#includecstdio>去掉.h,02myself.cpp文件2#include3#include4//#include<string.h>#include5usingnamespace7int8 //char string int cin>>name>> cout我是name出生于2014-age return18C语言中：gcc/ccxxx.cC++中：g++/c+xxx.cppgcc/ccxxx.cpp--c-S-o-Ousingnamespace命名空间的学习和使用2#include3usingnamespace6namespace7 intg_balance0;// voidsave(int g_balance+= voiddraw(int g_balance-= 1921namespace2223 intg_balance=0; voidsave(intmoney) g_balance+= voiddraw(int g_balance-= }}cout农行账户的余额是：g_balance{void3739int40 usingnamespace //usingnamespaceabc;两种选择,可以选择两个版本的同名函数和变量， 50 std::cout<<"账户余额是：g_balance="<<abc::g_balance<< using return58自定义命名空间{}使用名字空间的方式usingnamespace作用域限定符，相当于"的std::cout大家好才是真的好usingstd::cout;usingcout大家好才是真的好无名名字空间2#include3usingnamespace56intg_data=78namespace9 intg_data= void cout<<"g_data="<<g_data<< 1517int18 usingnamespace show200 //coutg_datag_dataendl23 cout<<"ns1中：g_data="<<ns1::g_data<<endl;//200 cout<<"全局变量中：g_data="<<::g_data<<endl;// return26扩12#include3usingnamespace5namespace6 intg_balance=89namespace10 voidsave(int g_balance+= 1516namespace17 voiddraw(int g_balance-= 22 25namespace26 intg_balance= 29 voiddraw(intmoney);30}32voidabc::save(int33 g_balance+=3536voidabc::draw(int37 g_balance-=3941int42 usingnamespace cout<<"g_balance="<<g_balance<< cout<<"g_balance="<<abc::g_balance<< return522#include3usingnamespace5namespace6 namespace namespace void cout<<"我们 是：没有蛀牙"<< 1719int20 namespacens1= return27结构体、联合、枚举的不同结构体中的不同 */{... 个完整的数据类型*/typedefstruct typedef structStudent{.[struct]Student员变量时不需要.->之类的(1)C语言中如果一个函数的形参表为空时，表示可以接(2)C++中如果一个函数的形参表中为空时，表示不接受2#include3#include4usingnamespace6int7 struct int void /*struct*/Students= cout<< 是："<<<< 是："<<s.age<< cout<<"------------------"<< Student*ps= cout<<"----------------"<< Students2= return32 为什么ss2show函数而打印出来的数据联合的不同之处[union]unu;12#include3#include4usingnamespace6int7 //union int char x= for(inti=0;i<4; returnreturnprintf("&x=%p,buf=}29枚举的不同之处09enum.cpp文件1C++2#include3usingnamespace5int6 enum /*enum*/COLORc= cout<<"c="<<c<<endl; //c0intCOLOR //cout<<"c="<<c<< intic;/COLORint cout<<"i="<<i<< i= cout<<"i="<<i<< return194.类型以及运算符的别4.1类bool#include<stdbool.h>：truefalse,110bool.cpp1C++bool2#include3usingnamespace5int6 boolgender= boolsex= cout<<(gender?"帅哥 ")<< cout<<"gender="<<gender<<",sex="<<sex<< boolalpha表示输出的格式：true 13 cout<<boolalpha<<"gender="<<gender<<",sex="<<sex<<endl; ="<<sizeof(gender)<< cout<<"-------------------"<< boolflag= cout<<"flag="<<flag<< flag= cout<<"flag="<<flag<< flag= cout<<"flag="<<flag<< flag=12> cout<<"flag="<<flag<< return264.2运算符别名&&&|strings; (4)贝尔Ｂ语言，在B语言的基础上修改和扩展，NewB语言，后来改名为C语言，出生于1972年在C语言的基础上，BS扩展C语言，NewC1998年出现C++的标准C+年C++98修订 年C++11标准C++兼容C，提供了的特性a.语言风格更加简洁d.e.f.头文件：.hpp.h#include<iostream>#include<cstdio>coutcing++/c++gcc/ccxxx.cpplstdc++usingnamespace{}usingnamespacestd::cout大家好才是真的好usingstd::cout;usingstd::endl;cout大家好才是真的好：truebool类型可以定义变量，作为函数的返回值和参数，也可&&and&|| |bitor(2)动态内存2#include3usingnamespace5intfoo(int6intfoo(void){7intfoo(inti,intj){9//intfoo(intj,int11//voidfoo(inti,int12intfoo(inti,doubled){}//1312intfoo(inti,doubled){}//15struct16 void1819struct20 void24int25 return272#include3usingnamespace5namespace6 voidfoo(int cout"ns1::fooii 1113namespace14 voidfoo(double cout"ns2::foodd 1921int22 usingnamespace usingnamespace using foo(66);// using return38ns1::foo中i=66ns2::food3.14ns1::foo中i=66ns1::foo中i=3ns1::foo中i=66ns2::food3.1403overload.cpp03overload.cpp2#include3usingnamespace5charint6voidbar(char*p,int7 coutbar(1)函数910char*constchar*11voidbar(constchar*p,char12 coutbar(2)函数1416shortchar17voidfun(char18 coutfun(1)函数2021shortint22voidfun(int23 coutfun(2)函数2526shortlonglong27voidfun(longlong28 coutfun(3)函数3032int->...33voidhum(double34 couthum(1)函数3637doubleint38voidhum(inti,int39 couthum(2)函数4143int44 //char* short return5312#include3usingnamespace5voidshow(inti,int6 89voidshow(inti,double10 coutshow(2)函数中,iidd1214int15 return19voidshow(inti,intj){}=>_Z4showiivoidshow(intj,int =>以满足C程序可以直接调用C++模块中的函数12#include3usingnamespace6extern"C"voidshow(inti,int78coutshow函数中：iij9}05main.c文件3//3//进行函数 4voidshow(inti,int5//void_Z4showii(inti,int7int8 return12voidfoo(inti,charc='A',char*p=NULL){...}foo(66,'B');//p= //c='A',p=voidfoo(inti,charc='A',char*p){}//errorvoidfoo(inti,charc='A',char*p=NULL);voidfoo(inti,charc,char*p){}112#include3usingnamespace5//函数 [1~3]6voidfoo(inti,charc='A',char*p=718voidfoo(int9 coutfoo函数中:ii1113int14 //foo(); return202223voidfoo(inti,charc,char*24p?p:"空指针26在有三个参数的foo函数中：i=66,c=B,p foo函数中：i66,cB,p空指针voidfnC语言中表示可以接受任意多个任意类型的实参;C++中表示不接受任何实参2#include5int6 return912int13 15fn();//errorfn(66);//ok类似于C语言中的宏函数，可以进行指令的替换，相对函数有09inline.cpp文件12#include3usingnamespace5inlineintsquare(int6 return810int11 for(inti=1;i<100000; return17分别使用inline修饰和不修饰去观察是否内联 10malloc.cpp2#include3#include4usingnamespace6int7 int*p= *p= cout<<"*p="<<*p<< p= p= for(inti=0;i<10; p[i]= cout<<"p["<<i<<"]="<<p[i]<< p= return23int*pi=newint;deletepi;pi=NULL;int*pi=newint(66);deletepi;pi=NULL;int*pi=newint[10];deletepipiNULL;int*pi=newint[10]{...};delete[]pi;pi=NULL;1//newdelete2#include3usingnamespace5int6 int*pi=new *pi= cout<<"*pi="<<*pi<< delete pi= pi=new cout<<"*pi="<<*pi<< delete pi= cout<<"-----------------"<< pi=new for(inti=0;i<5; pi[i]= cout<<"pi["<<i<<"]="<<pi[i]<< delete[] pi= cout<<"-------------"<< pi=new for(inti=0;i<5; cout<<"pi["<<i<<"]="<<pi[i]<< delete[] pi= //pi=new //int**ppi=new return40int*pi=newint;//okint*pi=newint[5];//okint*pi=newint[3][4];//errorint**pi=newint[3][4];int(*pi)[4]=newint[3][4];delete[]pi;pi=NULL;int(*pi)[3][4]=newint[2][3][4];delete[]pi;pi=NULL;1//newdelete2#include3usingnamespace5int6 int(*pi)[4]=new for(inti=0;i<3; for(intj=0;j<4; pi[i][j]= cout<<"pi["<<i<<"]["<<j<<"]="<<pi[i][j] delete[] pi= cout<<"----------------"<< pi=new for(inti=0;i<3; for(intj=0;j<4; cout<<"pi["<<i<<"]["<<j<<"]="<<pi[i][j] delete[] pi= cout<<"---------------"<< int(*qi)[3][4]=new delete[] qi= return3612#include3usingnamespace5int6 int*pi=new cout<<"*pi="<<*pi<< delete pi= shortbuf[24 int*q=new(buf) cout*qshowbase/*0x*hex/*十六进制**q<< cout<<buf[0]<<''<<buf[1]<< cout<<"q="<<q<<",buf="<<buf<< return18*pi=*q=0x 0x56780x1234q=0xbf8d72ec,buf=3.1并不是一种独立的数据类型，类似于Cinta=10;int&b=ab,bint&c==>int&c=a;c=int&a;//errorint*pa(2)不可以为空，指针可以为空int&a=NULL;//errorconstint&a=NULL常constint&a=11;//okint*pi=NULL;//空指针inta=10;int&b=a;intm=bmam;int*pi=&a;pi=&b;int&arr[10];//errorint*arr[10];//okintarr[10];//okint(*arr)[10];在C++程序尽量去使用，而少使用指针，因为指针容易出现野指针，typedefvoidvoidfn(inti,charc='A',char*p=intC语言中：malloc/calloc/realloc/free除了对Cint*pi=newint;deletepi;pi=NULL;int*pi=newint(66);deletepi;pi=NULL;int*pi=newint[5];delete[]pi;pi=NULL;int*pi=newint[5]{...};delete[]pi;pi=NULL;申请N维数组返回N-1维的数组指针int(*pi)[4]=newnew指针数据类型(初始值|inta=int&b=a;//a起别名bint&cbctypedefvoidtypedefvoid(*)(int)void(*)(int)signal(intsignum,void(*)(int)handler);void(*signal(intsignum,void(*handler)(int)))(int);针int*pi;int*int*pi;int&b=a;int&b=a;int&ba;//效果一样int&b=a;int&ma,&nb;//(3起别名的方式去使用typedefint*PINT;typedefint&RINT;PINTi,jRINTma,nb两个inta=int*pa=&a;//一级指针int**ppa&pa;//二级指针int&b=a;//a起别名为bint&*pb=&b;//error可以定义指针的，不可以定义的inta=10;int*pa=&a;int*&ra=pa;//okint&b=a;int&&rb=b;//int*pa[5]指针数组int&pa[5];//errorint(&pa)[5];//数组01reference.cpp文件1 2#include3usingnamespace5值传递发生数据的拷贝6voidfn(int7 num=911voidfn2(int*12 *pn=15//通15//通 16voidfn3(int&17 rn=1922voidbar(char*23 ps=2527voidbar2(char**28 *pps=31 31 32voidbar3(char*&33 rps=3537int38 intnum= cout<<"num="<<num<< char*ps= cout<<"ps="<<ps<< return47 2#include3usingnamespace56voidswap1(inti,int7 inttemp= i= j=1113voidswap2(int*pi,int*14 inttemp= *pi= *pj=1820voidswap3(int&ri,int&21 inttemp= ri= rj=252728voidprint(constint&i,constint&29 cout<<"i="<<i<<",j="<<j<<3133int34 inti=10,j= cout<<"i="<<i<<",j="<<j<< cout<<"-----------------"<< print(i,j);//20, return45不要返回对局部变量(包括函数的形参)的,可以返回静态局部变量/全局变量/动态内存/实参的/成员变量的,这些返回值都是安全的1 1 2#include3usingnamespace45int&6 intnum= //cout<<"&num="<<&num<< return1012void13 inta= intb= //cout<<"&a="<<&a<<",&b="<<&b<<1719int&20 staticintnum= return2426intg_num=27int&28 return3032int&33 int*pi=new return3638int&foo5(int&39 return4143struct44 int int& return 5052int53 //int&rn= //cout<<"&rn="<<&rn<< //cout<<"rn="<<rn<< intnum= int&rn= cout<<"rn="<<rn<< S s.n= int&rm= cout<<"rm="<<rm<< return71charcintiint)cCintiint(cC++主要用于具有多态特性的父子类指针/之间的转换(以后讲到)04cast.cpp文件2#include3usingnamespace5int6char*char*void*void*pv=//pc=//void*->char*pc=//char*->void*pv= int* int*char //charc= char charint* //pi= //c=static_cast<char>(pi); //pi=static_cast<int*>(c); volatile/*易变的*constintnum //num=100; constint*int* //int*pn= int*pn= *pn= 100100 cout<<"num="<<num<<",*pn="<<*pn<< intn= //int*-> char*ps= cout<<"*ps="<<*ps<<endl; return40constenum(枚举)inline(内联)之#definePIconstdoublepi=#defineMAX(x,y)(x)>(y)?(x):(y)inlineintmax(intx,inty){return}05string.cpp1/string2#include3#include4usingnamespace6int7 //char*ps= strings= cout<<"s="<<s<< string cout<<"s2="<<s2<< strings3= cout<<"s3="<<s3<< s3= cout<<"s3="<<s3<< s=s+ cout<<"s="<<s<< s2+= cout<<"s2="<<s2<< if(s> cout字符串s比较大 cout<<"s[0]="<<s[0]<< cout<<"s[1]="<<s[1]<< c_str()const coutC风格字符串是：s.c_str couts的长度是：s.length char*ps= s= cout<<"s="<<s<< return40面向对象->大处着眼属性：学号为：吃饭学习属性：为：吃饭授课class{class{stringm_name;//intm_age;//{{}class{intm_age;voidlearn(conststring&lesson){...private{{}06class.cpp2#include3#include4usingnamespace6class78 int 12 voidlearn(conststring& 16 cout我是m_name今年m_age岁了，正在学习"<<lesson<<endl; boolsetName(conststring& if(0==returnreturn m_name= return boolsetAge(int if(age<0||age> return return m_age=}return string return int return Student(conststring&name,int m_name= m_age= 5658int59 //s.m_name= //s.m_age= cout<<"设 失败"<< return- cout<<"设 失败"<< return- cout<<s.getName()<<','<<s.getAge()<< cout<<"--------------"<< //string Student cout<<s2.getName()<<','<<s2.getAge()<< return85 2#include3#include4usingnamespace6class78 int 12 Girl(conststring&name,intage,bool m_name= m_age= m_bf= void 24 cout<<"我是"<<m_name<<",今年芳龄是"<<m_age<<","<<(m_bf ?"已经名花有主了":"还没有男朋友")<<endl; 2628void2930 cout我是m_name今年芳龄是m_age 花有主了":"还没有男朋友3133int34GirlGirl Girl return40int*pi;intint&ra=int&raa,&rbb;typedefint*PINT;typedefint&可以指针的，不可以的const修饰作为函数，避免了实参在函数中被修改，并且不要返回局部变量的，可以返回静态局部变量/reinterpret_cast主要用于任意类型的指针/之间的转换，{{{}控制符访控属性本类子类类外 protected保护的 okno ok no{{}{{}12#include3#include4usingnamespace6class78 string int11 void 14 cout我是m_name今年m_age岁了"<<endl; /*Student(conststring&name无名",intage m_name= m_age= 23 Student(conststring&name="",intage= m_name没名 m_age= 3133int34 Student Students2= Studentss[3]={Student",28),Student cout<<"---------------"<< Student*ps=new deleteps;ps= //ps=new ps=new delete[]ps;ps= cout<<"--------------"<< psnewStudent();// //psnewStudent deleteps;ps= return651 定义初始化的比较2#include3usingnamespace5class67 coutA被构造了 1315class1617 19 coutB 2426int27 B return30{{}class int string Dumy(conststring&intnum=10;自动调用构造函数进行初始化->执行构造函数体;2#include3usingnamespace5//intg_num=6class78 constintm_id;200// int&m_age;//=11 User(intid,int //m_age= void 19 cout<<"m_id="<<m_id<<",m_age="<<m_age<< 2123int24 User return28目标类::目标类(const源类&源类对象2#include3usingnamespace5 类6class9class1011 intintintint1516 explicitPoint3d(intx,inty=0,intz= void cout<<'('<<m_x<<','<<m_y<<','<<m_z<<<< 24};2627class2829 int int32 Point2d(intx,int void cout<<'('<<m_x<<','<<m_y<<')'<< friendclass42 46int47 Point3d Point2d cout<<"-------------"<< //Point3dPoint3d= //Point3dpt5100 Point3dpt5= return62classA{voidshow(Bint{BAa;}1//this2#include3#include4usingnamespace6class78 string int11 //Student(conststring&name,int Student(conststring&m_name,int //(*this).m_name=coutcout我是m_name今年m_age{void}cout在构造函数中：thisthisthis->m_age=this->m_name=//s.m_name="<< coutshow函数中：thisthis 2830int31 Student cout在主函数中：&s&s cout<<"-------------------"<< Student cout在主函数中：&s2&s2 return41保存调用对象/正在构造对象的地址11//this指针用于返回 2#include3usingnamespace6class78 10}}<<cout{void}return{Counter&}return{Counter&Counter(intcn=3032int33 Counter c.print();// return432#include3#include4usingnamespace667class10class1112 14 voideducate(Student* cout<<m_answer<< voidreplay(conststring& m_answer= 2931class3233 voidask(conststring&question,Teacher* cout<<question<< 3941voidTeacher::educate(Student*42 cout<<m_answer<<4749int50 Teacher Studentreturnreturn552#include3#include4usingnamespace6class78 string mutableint11 void 17 cout我是m_name今年m_age岁了"<<endl; voidsetName(conststring& m_name= m_age= // coutconst修饰的成员函数return string{cout普通成员函数return 3840int41 Student cout<<"获取到 是："<<s.getName()<< cout<<"-------------"<< constStudent&rs= cout<< 获取 是："<<rs.getName()<< constStudent*ps= cout<<"指针获取 是："<<ps->getName()<< return55constint*pi&i*pi不可变intconst*pi&i*pi不可变int*constpi=&i;//pi不可变constint*constpi;pi*pi ../day05/ 2#include3#include4#include5#include6usingnamespace8class910 int int int14 time_tt= structtm*pt= m_hour=pt-> m_min=pt->22 m_sec=pt->tm_sec; void if(60== m_sec= if(60== m_min= if(24== m_hour= void coutr'/*回车不换行*/<<setfill('0')/*0* <<flush/*刷新 / void 5860int61 Clock return65{{}{{}执行作业 2#include3#include4#include5#include6usingnamespace8class910 int int int14 time_tt= structtm*pt= m_hour=pt- m_minm_min=pt-m_sec=pt-m_sec=pt-} voidvoid{if(60=={m_sec=if(60=={m_min=if(24=={if(60=={m_sec=if(60=={m_min=if(24=={m_hour=}}}}void{cout<<'\r'/*回车不换行*/<<setfill('0')/*空位填0* setw(2m_secflush/*刷新 void 5557int58 Clock return62{{}12#include3usingnamespace5class67 coutA被构造了 coutA 1820//A22int23 cout主函数开始 //A Areturnreturncout主函数结束pa=delete[]A*pa=newpa=delete/*A*pa=new39调用析构函数;而对于堆区的对象来说，当delete时会自动的资源不仅仅包括动态内存，还包括文件的关闭，socket的关闭等等03destruction.cpp文件12#include3usingnamespace5class67 coutA被构造了 coutA 1618class1920 A*22}}m_a=deletecoutB{}coutB被构造了{3335int36 //ABB B return40B被构造了析构B{{}StudentStudents2(s)调用拷贝构造Students3=s;//同上Student*psnew 2#include3#include4usingnamespace6class78 string int11 void 15 cout我是m_name今年m_age岁了"<<endl; cout自定义拷贝构造函数 2426int27 Student cout<<"------------------"<< Student Students3=s;//Student Student*ps=new deleteps;ps= // //s2= return43我我 我 我 a.b.2#include3#include4usingnamespace6class78 int11 m_pName=new delete[] m_pName= void cout我是m_pName今年m_age了 Student(constStudent& m_pName=new 3537int38 Student Student return4506copyConstruction.cpp12#include3usingnamespace5class67 cout自定义构造函数 A(constA& cout自定义拷贝构造函数 1618voidfoo(Aa){Aaa119Afoo(Aareturna;20/A&foo(Aa){returna;21//A&foo(A&a){returna;022因为局部变量生命周期短暂，构造完毕之后还得销毁，于是编译器优化，直接构造新23A24 A return2729int30 Aa1 A Aa3= A*pa=new cout<<"---------------"<< return39StudentStudents2s;//=>s2.operator=Student&operator=(constStudent&{return*this;}一个缺省拷贝赋值运算符函数，本质就是按照字节进行12#include3#include4usingnamespace6class78 int11 m_pName=new delete[] m_pName= void cout我是m_pName今年m_age了 Student(constStudent& m_pName=new Student&operator=(constStudent& if(this!=m_age=m_age=m_pName=newm_pName=delete[] return 5254int55 Student Student cout<<"----------------"<< Student s3= cout<<"---------------"<< intinta=10,b=20,c=(a=(a=b)=cout<<"a="<<a<< // (s4=s3)= return78static修饰局部变量：生命周期变长static修饰函数：防止其他文件使用{static数据类型静态成员变量名数据类型类名::静态成员变量名初始值08static.cpp08static.cpp2#include3usingnamespace5class67 int9 staticint12 void cout<<"m_data="<<m_data<< cout<<"s_data="<<s_data<< 22 staticint //cout<<"m_data="<<m_data<< return 3033intA::s_data=35int36 A cout<<"A::s_data="<<A::s_data<< cout<<"a.s_data="<<a.s_data<< a.s_data= A cout<<"a2.s_data="<<a2.s_data<< //Aa;sizeof(A)= cout<<"sizeof(A)="<<sizeof(A)<<endl;// cout<<"--------------------"<< cout获取的数据是：A::getData cout使用对象获取的数据是：a.getData return53{static返回值类型函数名( {}09static.cpp23#include4usingnamespace6class78 Singleton&operator=(constSingleton&15 staticSingleton19 staticSingleton& return 2427Singleton29int30 //Singletons1; Singleton&s1= cout<<"&s1="<<&s1<< Singleton&s2= cout<<"&s2="<<&s2<< Singleton&s3= cout<<"&s3="<<&s3<< //s1=s2; //cout<<"&s1="<<&s1<< return43Students;string*ps&类名::成员变量名返回值类型(类名::*指针名)(形参 &类名::成员函数名2#include3#include4usingnamespace6class7 voidsetName(conststring& m_name= 1517int18 string pName= Student //s.*(&m_name)=> s.*pName= cout<<"s.m_name="<<s.m_name<< cout<<"------------"<< Student s2.*pName= cout<<"s2.m_name="<<s2.m_name<< cout<<"-----------"<< 36 void(Student::*pSetName)(conststring&name)= //*pSetName=>*(&setName)=> // cout<<"s.m_name="<<s.m_name<< cout<<"s2.m_name="<<s2.m_name<< return45(2)双目运算符重载(3)单目运算符重载(4)不{{}{{}{ 象名{}{数据类型类名::变量名=初始值;{static返回值类型函数名( 参表{}&类名::成员变量名;(3)使用/解&类名::成员函数名(3)双目运算符重载(4)单目运算符重载(5)不intnum=cout<<num<<endl;//10charc='A';cout<<c<<endl;doubled=cout<<d<<endl;//3.14Students;cout<<s<<12#include3usingnamespace5classComplex//复数类67 intm_r 10 Complex(intr=0,inti= friendostream&operator<<(ostream&os,constComplex& friendistream& plex& is>>c.m_r>> return 2124ostream&operator<<(ostream&os,constComplex&25 os<<c.m_r<<'+'<<c.m_i<< return2830int31 Complex // // cout<<c1<< Complex cout<<"c2="<<c2<< coutostream cinistream // cin>> cout输入之后：c2c2 return472/32#include3usingnamespace5class67 int int10 F(ints=0,intm= friendostream&operator<<(ostream&os,constF& // // os<<f.m_s<<'/'<< return friendistream&operator>>(istream&is,F& is>>f.m_s>> return 2628int29 F cout<<"f="<<f<< cin>> cout<<"f="<<f<< return36-12#include3usingnamespace5classComplex//复数类67 intm_r 10 Complex(intr=0,inti= friendostream&operator<<(ostream&os,constComplex& friendistream& plex& is>>c.m_r>> return 22 Complexoperator+(constComplex&c)const 对象返 return Complexoperator-(constComplex&c) Complex&operator+=(constComplex& /*m_r+= m_i+= return return*this=*this+ Complex&operator-=(constComplex& /*m_r-=44 m_i-=c.m_i; return*this=*this-} cout非成员形式的重载 return //int类型之间的+ Complexoperator+(int return 6063ostream&operator<<(ostream&os,constComplex&64 os<<c.m_r<<'+'<<c.m_i<<66 67}69int70 Complex // // cout<<c1<< Complex cout<<"c2="<<c2<< coutostream cinistream // cin>> cout输入之后：c2c2 cout<<"-------------------"<< //Complexc3=88 //Complexc3=operator+(c1,c2); //c3.operator=(c1.operator+(c2)); Complexc3=c1+ cout<<"c3="<<c3<< cout<<"c3-c2="<<c3-c2<< cout<<"------------------"<< inta=10,b= (a+=b)+= cout<<"a="<<a<< cout<<"c1="<<c1<< cout<<"c2="<<c2<<//(c1+=c2)+=cout<<"c1="<<c1<<(c1-=c2)-=cout<<"c1="<<c1<<endl;cout<<"-----------------"<<cout<<"c1="<<c1<<//cout<<"c1+100="<<c1+100<<return111L/*左操作数*/*运算符*R(右操作数s+=>=>运算符重载1/2+1/3=3/6+2/6=5/62#include3usingnamespace5class67 int int10 F(ints=0,intm= friendostream&operator<<(ostream&os,constF& // // os<<f.m_s<<'/'<< return friendistream&operator>>(istream&is,F& is>>f.m_s>> return Foperator+(constF&f) return Foperator-(constF&f) F&operator+=(constF& return*this=*this+ F&operator-=(constF& return*this=*this- 4446int47 Fcoutcout<<"f2="<<f2<<cin>>Fcout<<"f="<<f<< cout<<"---------------"<< // cout<<"f+f2="<<f+f2<< cout<<"f-f2="<<f-f2<< // coutff2的结果：ff2 coutff2的结果是：ff2 return63=>operator#(O);12#include3usingnamespace5class67 int int10 Complex(intr=0,inti= friendostream&operator<<(ostream&os,constComplex& returnos<<c.m_r<<'+'<<c.m_i<<}}{} Complexc= return friendconstComplexoperator++(Complex& Complexc1= return Complex& 44 constComplexoperator-- Complexc= return return 6163int64 Complex66 cout<<"c1="<<c1<<endl; //c1.operator-(); cout<<"-c1="<<-c1<< cout<<"--------------------"<< intm= cout<<"m++="<<m++<< cout<<"m="<<m<<75 //(m++)++;//m++返回的是++之前的临时值，并不是m本身，临时值不能再 //cout<<"m="<< intn= cout<<"++n="<<++n<< cout<<"n="<<n<<endl;// C++++n cout<<"n="<<n<< cout<<"--------------------"<< cout<<"c1="<<c1<<87 //c1.operator++(int) //operator++(c1,int); cout<<"c1++="<<c1++<< cout<<"c1="<<c1<< //(c1++)++; //cout<<"c1="<<c1<< // cout<<"++c1="<<++c1<< cout<<"c1="<<c1<< cout<<"c1="<<c1<<cout<<"-----------------"<<cout<<"c1--="<<c1--<<cout<<"c1="<<c1<< cout<<"--c1="<<--c1<<cout<<"c1="<<c1<< cout<<"c1="<<c1<<return109数只有一个参数-操作数符函数有两个参数，第一个是操作数，第二个是int类型的哑元2#include3usingnamespace5class67 int int10 F(ints=0,intm= friendostream&operator<<(ostream&os,constF& returnos<<f.m_s<<'/'<< // returnF(- F& return constF Ff= return 3638int39 F cout<<"f="<<f<< cout<<"-f="<<-f<< cout<<"f++="<<f++<< cout<<"f="<<f<< cout<<"++f="<<++f<< return47{}07conversion.cpp2#include3usingnamespace5class7class89 int int int13 Point3d(intx,inty,int returnos<<'('<<pt3.m_x<<','<<pt3.m_y<<<<pt3.m_z<< 2325class2627 int int30 Point2d(intx,int operator cout类型转换运算符函数 return 43 friendclassPoint3d;44}; 48int49 Point3d cout<<"pt3="<<pt3<< Point2d cout<<"pt2="<<pt2<< //pt2.operator //pt3pt2 //pt3= cout<<"pt3="<<pt3<< return61-.-成员操作.*如：*push在数组的尾部插入一个元素pop()在数组的尾部弹出一个元素get()根据下标获取一个元素的值set() 12#include3usingnamespace5class67 intm_len intm_pos11 IntArray(intlen):m_arr(newint[m_len= delete[] m_arr= boolpush(int if(m_pos== return return m_arr[m_pos++]= return boolpop(int& if(0== return return num=m_arr[-- return boolget(intpos,int& }}cout<<}cout<<m_arr[i]<<'{for(inti=0;i<m_pos;{void}returnm_arr[pos]=}return{if(pos<0||pos>={boolset(intpos,int}returnnum=}return{if(pos<0||pos>=7173int74 IntArray for(inti=0;i<10; cout<<boolalpha<<ia.push(10)<< cout<<"--------------"<< intnum= cout<<"num="<<num<<cout<<"num="<<num<< cout<<"-------------"<< cout96 for(inti=0;i<10;i++) cout<<num<<' cout<<cout<<ia.pop(num)<<return104(2)new/delete操作符的重载intnum=//cout.operator<<(int);cout<<num<<endl;Students;////cout<<s<<friendoperator<<(ostream&os,constStudent&////cinistreamcin>>friendopertor>>(istream&is,Student&L.operator#(R);operator#(L,R);Complex////operator+(c1,c2);cout<<c1+c2<<endl;operator#(O);Complex//operator-(c);cout<<-c<<endl;数，第二个是int类型的哑元{}::..*?:sizeof(2)new/delete操作符的重载2#include3usingnamespace5class67 int* int int11 IntArray(intlen):m_arr(newint[m_len= }}return{intoperator[](int}cout<<}cout<<m_arr[i]<<'{for(inti=0;i<m_pos;{void}returnm_arr[m_pos++]=}return{if(m_pos=={boolpush(int}m_arr=delete[]4143int44 IntArray for(inti=0;i<5; 48 cout<<"---------------"<< for(inti=0;i<5; // cout<<ia[i]<<' cout<< return601函数操作符()2#include3usingnamespace5class67 intoperator()(int return doubleoperator()(double return 1719int20 Square // cout计算的结果是：s(1024 cout<<"计算的结果是："<<s(3.14)<<endl; return0;26*1*2#include3usingnamespace5class67 coutA被构造了 cout析构Ａ void coutfoo()函数调用了 2022class2324 A*26 PA(A* delete m_pa= return A& return 4446int4748 //A*pa=newA; //delete //pa= PApa(new //pa.operator->()- //pa.operator*() return581//newdelete2#include3#include4usingnamespace6class79 int11 coutA被构造了 cout析构Ａ staticvoid*operatornew(size_t void*p= << return staticvoidoperatordelete(void* coutDelete中：pp p= staticvoid*operatornew[](size_t void*p= << return staticvoidoperatordelete[](void* coutdelete[]中：pp}}p=4749class5051 coutB被构造了 cout析构Ｂ 6062int63 A*pa=new delete pa= cout<<"---------------"<< //A*pa2= << delete[] pa= cout<<"------------------"<< B*pb=new delete pb= return84可以通过new/delete运算符重载的函数来实现publicprotectedprivate属性：学行为：吃饭学习属性：行为：吃饭授课属性： 12#include3#include4usingnamespace6 78string911 15 cout<<"我是"<<m_name<<"，今年"<<m_age<<"岁了"<<endl; voideat(conststring& coutfood真好吃 string return 29 32classStudent: 3334 cout我是学生，我的学号是：m_id voidlearn(conststring& cout正在学习lesson //cout学号是：m_id void //cout<<"m_name="<<m_name<< cout是：getName{int//inteat(conststring&//voideat(conststring&}吃 6264int65 Student /*cout<<"------------------"<< 72 *p=newStudent(" //p cout<<"----------------"<< cout<<"--------------"<< return88{public:公有方式继承private:私有方式继承12#include3#include4usingnamespace6 78 string int11 14 cout<<"我是"<<m_name<<"，今年"<<m_age<<"岁了"<<endl; voideat(conststring& coutfood真好吃 2022classTeacher: 2324 string2627 Teacher(conststring&name,intage,conststring& cout<<"我是教师 是："<<m_job<< voideducate(conststring& cout我在教lesson 3537int38 Teacher return43控class{void classB:private{void{}class{2#include3usingnamespace5class67 coutA被构造了 coutA 1618classB:public1920 coutB被构造了 coutB 2931int32 ABB析构 B*pb=new delete pb= cout<<"-------------------"<< AB A*pa=new delete pa= return44(1)[(3)*void*operatornew(size_t{}voidoperatordelete(void*{}void*operatornew[](size_t{ 信}voidoperatordelete[](void*{}/StudentTeacher(子类/派生类{}2#include3#include4usingnamespace6 78 string int11 15 cout我是m_name今年m_age岁了"<<endl; (const & cout 自定义拷贝构造函数 2224classTeacher:public 25{26 28 30 Teacher(conststring&name,intage,conststring& cout<<"我是教师，我 是："<<m_job<< Teacher(constTeacher& cout自定义拷贝构造函数 3941int42 Teacher return46{ 2#include3usingnamespace5class67 int9 A(intn= coutA 1518classB:virtualpublic1920 B(intn= 24 cout<<"构造B"<<endl; voidset(int m_n=