新建 文本文档.txt

资深C++讲师授课代码

        //cout << *&furong << endl;//Person*
        cout << *&furong.name << endl;//string*
        cout << "sizeof(furong)=" << sizeof(furong) << endl;
        cout << "sizeof(furong.name)=" << sizeof(furong.name) << endl;
        cout << "sizeof(furong.gender)=" << sizeof(bool) << endl;
        cout << "sizeof(furong.age)=" << sizeof(furong.age) << endl;
        cout << "sizeof(furong.income)=" << sizeof(double) << endl;
        cout << "&furong.name=" << &furong.name << endl;
        cout << "&furong.gender=" << &furong.gender << endl;
        cout << "&furong.age=" << &furong.age << endl;
        cout << "&furong.income=" << &furong.income << endl;
}


bash-2.05$ cat charptr.cc
#include <iostream>
using namespace std;

int main()
{
        char a[10]={"good"};
        char* p = a;
        const char* q = "afternoon";
        p[2] = 'O';
        //q[2] = 'X';//ERROR!!
        char* r = "everyone";//danger!!!!
        //r[2] = '*';//runtime error!!!segementation fault!!!
        cout << a << endl;
        cout << q << endl;
        cout << r << endl;
        //char* x;//野指针!!!
        //cin >> x;//试图用指针本身来保存字符串，不允许!!!!
}


bash-2.05$ cat ptr2ptr.cc
#include <iostream>
using namespace std;

int main()
{
        double d=123.45;
        double* p = &d;
        double** q = &p;
        cout << *p << endl;
        cout << **q << endl;
}


bash-2.05$ cat struct.cc
#include <iostream>
using namespace std;
#include <string>

struct Person{
        string name;
        bool gender;
        int age;
        double income;
};
void show(Person obj);
Person input();
const char g[2][10]={"美女","帅哥"};
int main()
{
        Person cyh;
        cyh.name = "程一航";
        cyh.gender = true;
        cyh.age = 21;
        cyh.income = 800;
        Person ljq = {"刘家奇", true, 22, 600};
        Person gy;
        gy = cyh;
        gy.name = "郭英";
        gy.gender = false;
        gy.age = 18;
        cout << cyh.name << ':' << g[cyh.gender] << "，今年" << cyh.age << "，未

婚，月收入" << cyh.income << "元。" << endl;
        //cout << cyh << endl;
        show(ljq);
        show(gy);
        Person quange;
        quange = input();
        show(quange);
}
void show(Person obj)
{
        cout << obj.name << ':' << g[obj.gender] << "，今年" << obj.age << "，未

婚，月收入" << obj.income << "元。" << endl;
}
Person input()
{
        cout << "请输入姓名、性别、年龄和月收入: " << endl;
        Person p;
        cin >> p.name >> p.gender >> p.age >> p.income;
        return p;
}


bash-2.05$ cat array.cc
#include <iostream>
using namespace std;

int main()
{
        int a[5]={10,20,30,40,50};
        char b[8]={"abcdefg"};
        int* pa = a;
        char* pb = b;
        for(int i=0; i<5; i++)
                cout << pa[i] << ' ';
        cout << endl;
        for(int i=0; i<8; i++)
                cout << pb[i] << ' ';
        cout << endl;
        cout << "pb=" << pb << endl;
        for(int i=0; i<5; i++)
                cout << *(pa+i) << ',';
        cout << endl;
        for(int i=0; i<5; i++)
                cout << *(pa++) << ' ';
        cout << endl;
        pa -= 5;
        cout << "pa=" << pa << endl;
        pa = a;
        cout << "pa=" << pa << endl;
        for(int i=0; i<5; i++)
                pa[i] *= 8;
        for(int i=0; i<5; i++)
                cout << a[i] << ' ';
        cout << endl;
}


bash-2.05$ cat enum.cc
#include <iostream>
using namespace std;

enum Color{BLACK, YELLOW, GREEN, BLUE, RED, WHITE, PINK};
enum Cloth{COAT=5, SHIRT, TROUSERS=11, SKIRT, CAP, SOCKES, SHOES};
enum Flags{NONE=0, EXECUTE=1, WRITE=2, READ=4, RDWR = WRITE|READ, RDEX=READ|EXEC

UTE, WREX=WRITE|EXECUTE};
int main()
{
        Flags perm=RDWR;
        //Flags p = (Flags)6;
        Cloth cth = CAP;
        //Cloth ct = (Cloth)13;
        Color clr = GREEN;
        //Color cl = (Color)2;
        //cl = SKIRT;//ERROR!!
}


bash-2.05$ cat ptrarr.cc
#include <iostream>
using namespace std;

int main()
{
        int a, b, c;
        int* x[3]={&a, &b, &c};
        for(int i=0; i<3; i++)
                *x[i] = 10+i;
        cout << "a=" << a << endl;
        cout << "b=" << b << endl;
        cout << "c=" << c << endl;
}


bash-2.05$ cat structarr.cc
#include <iostream>
using namespace std;
#include <string>

struct Person{
        string name;
        bool gender;
        int age;
        double income;
};
void show(Person obj);
int main()
{
        Person nmgd[3]={
                {"程一航", true, 21, 800},
                {},
                {"郭英", false, 18, 800}
        };
        nmgd[1].name = "刘家奇";
        nmgd[1].gender = true;
        nmgd[1].age = 22;
        nmgd[1].income = 700;
        for(int i=0; i<3; i++)
                show(nmgd[i]);
}
void show(Person obj)
{
        const char g[2][10]={"美女","帅哥"};
        cout << obj.name << ':' << g[obj.gender] << "，今年" << obj.age << "，未

婚，月收入" << obj.income << "元。" << endl;
}


bash-2.05$ cat arraypara.cc
#include <iostream>
using namespace std;

//void func(double a[], int n)
void func(double* a, int n)
{
        cout << "sizeof(a)=" << sizeof(a) << endl;
        //a = NULL;
        for(int i=0; i<n; i++)
                cout << a[i] << ' ';
        cout << endl;
}
int main()
{
        double b[3] = {1.1,2.2,3.3};
        cout << "sizeof(b)=" << sizeof(b) << endl;
        func(b, 3);
        //b = NULL;//ERROR!!
}


bash-2.05$ cat input.cc
#include <iostream>
using namespace std;

int input()
{
        cout << "input an integer: ";
        int n;
        cin >> n;
        return n;
}
void input(int* p)
{
        cout << "input an integer: ";
        cin >> *p;
}
void input(int& n)
{
        cout << "input an integer: ";
        cin >> n;
}
int main()
{
        int m;
        m = input();
        cout << "m=" << m << endl;
        input(&m);
        cout << "m=" << m << endl;
        input(m);
        cout << "m=" << m << endl;
}


bash-2.05$ cat ptrpara.cc
#include <iostream>
using namespace std;

void func(double* x, double* y);
void func(double m, double n)
{
        double t=m;
        m = n;
        n = t;
}
int main()
{
        double a=1.1, b=2.2;
        func(a, b);
        cout << "a=" << a << ", b=" << b << endl;
        double* p=NULL;
        double* q=NULL;
        p = &a;
        q = &b;
        double t=*p;
        *p = *q;
        *q = t;
        cout << "a=" << a << ", b=" << b << endl;
}


bash-2.05$ cat structptr.cc
#include <iostream>
using namespace std;

struct Date{
        int year;
        int month;
        int day;
};
int main()
{
        Date d1={2008,8,14}, d2={2005,10,1};
        Date* p=NULL;
        p = &d1;// p point to d1
        cout << (*p).year << '-' << (*p).month << '-' << (*p).day << endl;
        cout << p->year << '-' << p->month << '-' << p->day << endl;
        p = &d2;
        cout << p->year << '-' << p->month << '-' << p->day << endl;
}



cpp07


bash-2.05$ cat constructor.cc
#include <iostream>
using namespace std;

class Date{
//private:
        int year;
        int month;
        int day;
public:
        Date(){
                cout << "无参构造函数" << endl;
                year = month = day = 1;
        }
        Date(int y, int m, int d){
                cout << "三参构造函数" << endl;
                year = y;
                month = m;
                day = d;
        }
        void set(){
                year = 2008;
                month = 8;
                day = 15;
        }
        void print(){
                cout << year << "年" << month << "月" << day << "日" << endl;
        }
        bool leap(){
                if(year%4==0&&year%100!=0||year%400==0)
                        return true;
                return false;
        }
        void set(int y, int m, int d){
                year = y;
                month = m;
                day = d;
        }
};
int main()
{
        Date d;//={2008,8,15};
        Date o(2020, 9, 9);
        Date func();//function declaration
}



bash-2.05$ cat funcptr3.cc
#include <iostream>
using namespace std;

struct Person{
        char name[20];
        bool gender;
        int age;
        double income;
};
bool isFemale(Person p)
{
        if(p.gender==false)
                return true;
        else
                return false;
}
bool age20(Person p)
{
        if(p.age>=20)
                return true;
        else
                return false;
}
bool lowIncome(Person p)
{
        if(p.income<1000)
                return true;
        else
                return false;
}
void select(Person s[], int n, bool(*f)(Person))
{
        for(int i=0; i<n; i++)
                if(f(s[i]))
                        cout << s[i].name << endl;
}
int main()
{
        Person s[3]={
                {"程一航", true, 21, 800},
                {"李燕成", true, 20, 1000},
                {"郭英", false, 18, 900}
        };
        cout << "选美女!" << endl;
        select(s, 3, isFemale);
        cout << "选年龄够20的人!" << endl;
        select(s, 3, age20);
        cout << "选收入低于1000的人!" << endl;
        select(s, 3, lowIncome);
}


bash-2.05$ cat reference.cc
#include <iostream>
using namespace std;

void show(const int& n)
{
        cout << "&n=" << &n << ", n=" << n << endl;
}
int main()
{
        int m=10;
        cout << "&m=" << &m << ", m=" << m << endl;
        show(m);
        show(123);
        show(m*5);
}


bash-2.05$ cat voidptr.cc
#include <iostream>
using namespace std;

void show(void* addr, int bytes)
{
        unsigned char* p = (unsigned char*)addr;
        for(int i=0; i<bytes; i++)
                cout << hex << (int)*(p+i) << ' ';
        cout << endl;
}
struct Person{
        char name[8];
        int age;
};
int main()
{
        int a=1234567890;
        bool b=true;
        char c='2';
        double d=1.2;
        Person fr={"furong", 38};
        show(&a, sizeof(a));
        show(&b, sizeof(b));
        show(&c, sizeof(c));
        show(&d, sizeof(d));
        show(&fr, sizeof(fr));
}


bash-2.05$ cat array.cc
#include <iostream>
using namespace std;

int main()
{
        unsigned int n;
        cout << "input the number of element: ";
        cin >> hex >> n;
        double* p = new double[n];
        cout << "p=" << p << endl;
        for(unsigned int i=0; i<n; i++)
                cout << p[i] << ' ';
        cout << endl;
        cout << "p=" << p << endl;
        for(unsigned int i=0; i<n; i++)
                cout << *p++ << ' ';
        cout << endl;
        cout << "p=" << p << endl;
        p = p - n;
        cout << "p=" << p << endl;
        delete[] p; p=NULL;
}



bash-2.05$ cat funcptr.cc
#include <iostream>
using namespace std;

struct Person{
        char name[20];
        bool gender;
        int age;
        double income;
};
bool isFemale(Person p)
{
        if(p.gender==false)
                return true;
        else
                return false;
}
bool age20(Person p)
{
        if(p.age>=20)
                return true;
        else
                return false;
}
bool lowIncome(Person p)
{
        if(p.income<1000)
                return true;
        else
                return false;
}
void select(Person s[], int n, bool(*f)(Person))
{
        for(int i=0; i<n; i++)
                if((*f)(s[i]))
                        cout << s[i].name << endl;
}
int main()
{
        Person s[3]={
                {"程一航", true, 21, 800},
                {"李燕成", true, 20, 1000},
                {"郭英", false, 18, 900}
        };
        cout << "选美女!" << endl;
        select(s, 3, &isFemale);
        for(int i=0; i<3; i++)
                if(isFemale(s[i]))
                        cout << s[i].name << endl;
        cout << "选年龄够20的人!" << endl;
        select(s, 3, &age20);
        for(int i=0; i<3; i++)
                if(age20(s[i]))
                        cout << s[i].name << endl;
        cout << "选收入低于1000的人!" << endl;
        select(s, 3, &lowIncome);
        for(int i=0; i<3; i++)
                if(lowIncome(s[i]))
                        cout << s[i].name << endl;
}