参数初始化表，构造、析构函数，友元……

参数的初始化：

#include<iostream>using namespace std;class Time{public:int hour;//int hour = 15;//C++11里才可以（类没有存储的地方，故不能这么做）private:};class Time2{public:void display(){cout << this->hour << endl;}private:int hour;};int main(){Time t1 = { 1 };//只适用于public的成员Time2 t2;cout << t1.hour << endl;//cout << t2.hour << endl;//私有成员不能这么用了t2.display();return 0;}

构造函数、析构函数、参数初始化表：

#include<iostream>using namespace std;class Time2{public://构造函数名字与本类名Time2相同;而且没有类型，没有返回值Time2()//无】参数的构造函数{hour = -1;min = -1;}Time2(int h)//有】参数的构造函数（重载1）{hour = h;}Time2(int h, int m) :hour(h), min(m) {}//参数初始化表//有】参数的构造函数（重载2）~Time2()//只能有一个析构函数，（构造函数可以多个{cout << "析构函数已执行" ;display();cout << endl;}void display(){cout << this->hour <<':'<< this->min << endl;}private:int hour;int min;};int main(){//所有的Time2类会有析构函数的执行Time2 t1;//因构造函数赋值为-1Time2 t2(2);Time2 t3(3,15);return 0;}

对象的复制：

#include<iostream>using namespace std;class Time{public:Time(){hour = -1;min = -1;}void set(){hour = 10;min = 10;}void display(){cout << this->hour <<':'<< this->min << endl;}private:int hour;int min;};int main(){Time t1;Time t2;t2.set();//t2设置t1 = t2;//对象的赋值【对象的“整体”赋值】cout << "t1:" << endl;t1.display();Time t4(t2);//从t2复制出t4【对象的复制】cout << "t4:" << endl;t4.display();return 0;}

友元、友元类

#include <iostream>using namespace std;class Date;                 // 对Date类的提前引用声明class Time{public:Time(int, int, int);void display(Date&);// display()是成员函数，形参是Date类对象的引用private:int hour;int minute;int sec;};class Date                                       // 声明Date类{public:Date(int, int, int);friend void Time::display(Date &);// 声明Time类中的display函数为本类的【友元成员函数】Time可以用Date的这个private:int month;int day;int year;};Time::Time(int h, int m, int s)         // 定义Time类的构造函数{hour = h;minute = m;sec = s;}void Time::display(Date &d)          //定义display函数{cout << d.month << " / " << d.day << " / " << d.year << endl;// 输出年月日cout << hour << ":" << minute << " : " << sec << endl;// 输出时间}Date::Date(int m, int d, int y)   //类Date的构造函数{month = m;day = d;year = y;}int main(){Time t1(10, 13, 56);Date d1(12, 25, 2004);t1.display(d1);return 0;}

类模板：

格式：
         类模板名  <实际的类型名> 对象名（参数）；
         如，Compare  <int>  cmp(4, 7);

#include <iostream>using namespace std;template<class numtype>class Compare        // 定义类模板，名为Compare {public:Compare(numtype a, numtype b){x = a; y = b;}numtype max(){return (x>y) ? x : y;}numtype min(){return (x<y) ? x : y;}private:numtype x, y;};int main(){Compare <int> cmp1(3, 7);     // 定义cmp1，操作两个整数cout << cmp1.max() << " is the Maximum of two inteder numbers."<<endl;cout << cmp1.min() << " is the Minimum of two inteder numbers." << endl << endl;Compare<float> cmp2(45.78, 93.6);// 定义cmp2，操作两个浮点数cout << cmp2.max() << " is the Maximum of two float numbers."<<endl;cout << cmp2.min() << " is the Minimum of two floatnumbers."<<endl<<endl;Compare <char> cmp3('a', 'A'); // 定义cmp3，操作两个字符 cout << cmp3.max() << " is the Maximum of two characters."<<endl;cout << cmp3.min() << " is the Minimum of two characters."<<endl;return 0;}

const类型小结

（书上的图）