本文共 27575 字，大约阅读时间需要 91 分钟。
以下为了同屏看到更多代码，选择省略了函数间的空白行、一行实现某些函数等，参考本文代码的同时，请务必保持良好的代码规范！
#includeusing namespace std;class Box { public: // 构造函数 Box(){ }; // 带参数的构造函数 Box(double a, double b, double c):x(a), y(b), z(c){ } // 设置盒子大小 void setBox(double a, double b, double c) { x = a; y = b; z = c; } // 获取面积 double getArea() { return 2 * (x * y + y * z + z * x); } // 获取体积 double getVolume() { return x * y * z; } void display() { cout << "x: " << x << " y: " << y << " z: " << z; cout << " area: " << getArea(); cout << " volume: " << getVolume() << endl; }private: double x, y, z;};void main() { // 使用默认构造函数不需要Box b2(); Box b1; b1.setBox(1, 2, 3); b1.display(); // 使用带参数的构造函数，需要传入指定参数 Box b2(2, 3, 4); b2.display(); // 使用new运算符创建动态对象，需要用delete运算符销毁，否则会造成内存泄漏 Box* b3 = new Box(4, 5, 6); b3->display(); delete b3;}
输出结果：
x: 1 y: 2 z: 3 area: 22 volume: 6 x: 2 y: 3 z: 4 area: 52 volume: 24 x: 4 y: 5 z: 6 area: 148 volume: 120
#include#include using namespace std;template // 声明类模板class Compare { public: Compare(numtype a, numtype b):x(a), y(b){ } // 获取最大值 numtype max(){ return x > y ? x : y; } // 获取最小值 numtype min(){ return x > y ? y : x; } void display() { cout << "x: " << x; cout << " y: " << y; cout << " max: " << max(); cout << " min: " << min() << endl; }private: numtype x, y;};void main() { Compare c1(1, 2); c1.display(); Compare c2(22.2, 33.3); c2.display(); Compare c3("hello", "world"); c3.display();}
输出结果：
x: 1 y: 2 max: 2 min: 1 x: 22.2 y: 33.3 max: 33.3 min: 22.2 x: hello y: world max: world min: hello
#includeusing namespace std;class Student { public: Student(int n, double s): num(n), score(s){ }; void display() { cout << "num: " << num; cout << " score: " << score << endl; }private: int num; double score;};void main() { Student s[5] = { Student(101, 100.0), Student(102, 33.50), Student(103, 60.0), Student(104, 89.50), Student(105, 95.50) }; Student* p = s; for(int i = 0; i < 5; i ++) { if((i % 2) == 0) (p+i)->display(); }}
输出结果：
num: 101 score: 100 num: 103 score: 60 num: 105 score: 95.5
#includeusing namespace std;class Student { public: Student(int n, double s): num(n), score(s){ }; double getScore() { return score; } void display() { cout << "num: " << num; cout << " score: " << score << endl; }private: int num; double score;};void max(Student* p) { int k = 0; double max_score = 0; for(int i = 0; i < 5; i ++) { int cur_score = (p+i)->getScore(); if (max_score < cur_score) { k = i; max_score = cur_score; } } cout << "the student with the highest score is "; (p+k)->display();}void main() { Student s[5] = { Student(101, 55.0), Student(102, 33.50), Student(103, 60.0), Student(104, 89.50), Student(105, 95.50) }; Student* p = s; max(p);}
输出结果：
the student with the highest score is num: 105 score: 95.5
#includeusing namespace std;void main() { int* p; // C++11可改为p = new int[10]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; p = new int[10]; for(int i = 0; i < 10; i ++) { *(p+i) = i+1; } for(int j = 0; j < 10; j ++) { cout << *(p+j) << " "; } cout << endl; delete[] p;}
运行结果：
1 2 3 4 5 6 7 8 9 10
复数是由实部和虚部构成的数学对象。复数可以表示为 a + bi 的形式，其中 a 和 b 都是实数，i 是虚数单位，满足 i² = -1。
在这个表示中，a 是复数的实部，b 是复数的虚部。实部和虚部都是实数。两个复数相等当且仅当它们的实部相等并且它们的虚部相等。 与实数不同的是，复数之间存在着更加复杂的乘法和除法运算。例如，如果 z₁ = 2 +i 3，z₂ = - 4 + i 5，则彼此相乘将得到：z₁z₂ = - 22 + i 7。因此，除了一般的加法和减法外，还需要引入其他算术规则和操作来处理复数。 复数具有很多实际应用，例如物理、工程、金融、电子学等领域。在计算机科学中，复数被广泛应用于信号处理、数字图像处理、动画和游戏编程等方面。
代码把+-*/都写了，供参考
#includeusing namespace std;class Complex { public: Complex(double r, double i): real(r), imag(i) { } double getReal() { return real; } double getImag() { return imag; } void display() { cout << "(" << real << " ," << imag << ")" << endl; }private: double real, imag;};// (a, b)-(c, d) = (a+c, b+d)Complex operator+(Complex& c1, Complex& c2) { return Complex(c1.getReal() + c2.getReal(), c1.getImag() + c2.getImag());}// (a, b)-(c, d) = (a-c, b-d)Complex operator-(Complex& c1, Complex& c2) { return Complex(c1.getReal() - c2.getReal(), c1.getImag() - c2.getImag());}// (a, b)*(c, d) = (ac - bd, ad + bc)Complex operator*(Complex& c1, Complex& c2) { return Complex(c1.getReal() * c2.getReal() - c1.getImag() * c2.getImag(), c1.getReal() * c2.getImag() + c1.getImag() * c2.getReal());}// (a, b)/(c, d) = ((ac + bd) / (c^2 + d^2), (bc - ad) / (c^2 + d^2))Complex operator/(Complex& c1, Complex& c2) { double m = c2.getReal() * c2.getReal() + c2.getImag() * c2.getImag(); double real = (c1.getReal() * c2.getReal() + c1.getImag() * c2.getImag()) / m; double imag = (c1.getImag() * c2.getReal() - c1.getReal() * c2.getImag()) / m; return Complex(real, imag);}void main() { Complex c1(2, 3); cout << "c1 = "; c1.display(); Complex c2(-4, 5); cout << "c2 = "; c2.display(); cout << "c1 + c2 = "; (c1 + c2).display(); cout << "c1 - c2 = "; (c1 - c2).display(); cout << "c1 * c2 = "; (c1 * c2).display(); cout << "c1 / c2 = "; (c1 / c2).display();}
运行结果：
c1 = (2 ,3) c2 = (-4 ,5) c1 + c2 = (-2 ,8) c1 - c2 = (6 ,-2) c1 * c2 = (-23 ,-2) c1 / c2 = (0.170732 ,-0.536585)
#includeusing namespace std;class Complex { public: Complex(double r, double i): real(r), imag(i) { } Complex operator+(Complex& c); Complex operator-(Complex& c); void display() { cout << "(" << real << " ," << imag << ")" << endl; }private: double real, imag;};Complex Complex::operator+(Complex& c) { return Complex(real + c.real, imag + c.imag);}Complex Complex::operator-(Complex& c) { return Complex(real - c.real, imag - c.imag);}void main() { Complex c1(2, 3); cout << "c1 = "; c1.display(); Complex c2(-4, 5); cout << "c2 = "; c2.display(); cout << "c1 + c2 = "; (c1 + c2).display(); cout << "c1 - c2 = "; (c1 - c2).display();}
输出结果：
c1 = (2 ,3) c2 = (-4 ,5) c1 + c2 = (-2 ,8) c1 - c2 = (6 ,-2)
友元函数的概念是在 C++ 标准化之后引入的，VC6.0 是一个较为古老的编译器版本，发布于 1998 年，仅支持部分 C++98 的特性，并不支持 C++11、C++14或更高标准提出的许多新特性，包括现代意义上的友元函数。
虽然 VC6.0 可以定义和使用传统意义上的自由函数（非成员函数），但实际上它并没有真正支持友元函数。因此，在使用 VC6.0 时，您需要采用传统的方法来定义和访问类的私有成员。
#includeusing namespace std;class Complex { public: Complex() { real = 0; imag = 0; } Complex(double r, double i) : real(r), imag(i) { } double getReal() { return real; } double getImag() { return imag; } Complex operator+(Complex& c); friend Complex operator+(int& i, Complex& c); friend Complex operator+(Complex& c, int& i); void display() { cout << "(" << real << " ," << imag << ")" << endl; }private: double real, imag;};Complex Complex::operator+(Complex& c) { return Complex(real + c.real, imag + c.imag);}Complex operator+(Complex& c, int& i) { return Complex(c.getReal() + i, c.getImag());}Complex operator+(int& i, Complex& c) { return Complex(c.getReal() + i, c.getImag());}void main() { Complex c1(2, 3); cout << "c1 = "; c1.display(); Complex c2(-4, 5); cout << "c2 = "; c2.display(); cout << "c1 + c2 = "; (c1 + c2).display(); int i = 2; cout << "c1 + 2 = "; (c1 + i).display(); cout << "2 + c1 = "; (i + c1).display();}
输出结果：
c1 = (2 ,3) c2 = (-4 ,5) c1 + c2 = (-2 ,8) c1 + 2 = (4 ,3) 2 + c1 = (4 ,3)
#includeusing namespace std;class Matrix { private: int data[2][3];public: Matrix(); Matrix(const int (&arr)[2][3]); friend Matrix operator+(const Matrix& m1, const Matrix& m2); void display();};Matrix::Matrix() { for (int i = 0; i < 2; i++) { for (int j = 0; j < 3; j++) { data[i][j] = 0; } }}Matrix::Matrix(const int (&arr)[2][3]) { for (int i = 0; i < 2; i++) { for (int j = 0; j < 3; j++) { data[i][j] = arr[i][j]; } }}Matrix operator+(const Matrix& m1, const Matrix& m2) { Matrix m; for (int i = 0; i < 2; i++) { for (int j = 0; j < 3; j++) { m.data[i][j] = m1.data[i][j] + m2.data[i][j]; } } return m;}void Matrix::display() { cout << "{ "; for (int i = 0; i < 2; i++) { cout << (i == 0 ? "" : ", ") << "{"; for (int j = 0; j < 3; j++) { cout << (j == 0 ? "" : ", ") << data[i][j]; } cout << "}"; } cout << " }" << endl;}void main() { int arr1[2][3] = { { 1, 2, 3}, { 4, 5, 6} }; Matrix m1(arr1); int arr2[2][3] = { { 7, 8, 9}, { 10, 11, 12} }; Matrix m2(arr2); Matrix m3 = m1 + m2; cout << "m3 = "; m3.display();}
输出结果：
m3 = { {8, 10, 12}, {14, 16, 18} }
#includeusing namespace std;class Complex { private: double real, imag;public: Complex(); Complex(const double& r, const double& imag); friend Complex operator+(const Complex& c1, const Complex& c2); void display();};Complex::Complex() { real = 0; imag = 0;}Complex::Complex(const double& r, const double& i) : real(r), imag(i) { }void Complex::display() { cout << "(" << real << ", " << imag << ")" << endl;}Complex operator+(const Complex& c1, const Complex& c2) { return Complex(c1.real + c2.real, c1.imag + c2.imag);}void main() { Complex c1(3, 4); Complex c2(5, 6); cout << "c1 + c2 = "; (c1 + c2).display();}
输出结果：
c1 + c2 = (8, 10)
#include#include using namespace std;class String { private: char* p;public: String() { p = nullptr; } String(const char* s) { p = new char[strlen(s) + 1]; strcpy_s(p, strlen(s) + 1, s); } String(const String& other) { if (other.p == nullptr) { p = nullptr; } else { p = new char[strlen(other.p) + 1]; strcpy_s(p, strlen(other.p) + 1, other.p); } } void display() const { cout << p << endl; } friend bool operator==(const String& s1, const String& s2);};bool operator==(const String& s1, const String& s2) { return strcmp(s1.p, s2.p) == 0 ? true : false;}void main() { String s1("Hello"); String s2("World"); String s3(s1); String s4; s4 = "World"; if (s1 == s2) cout << "s1 equals to s2." << endl; else cout << "s1 doesn't equal to s2." << endl; if (s1 == s3) cout << "s1 equals to s3." << endl; else cout << "s1 doesn't equal to s3." << endl; if (s2 == s4) cout << "s2 equals to s4." << endl; else cout << "s2 doesn't equal to s4." << endl;}
输出结果：
s1 doesn’t equal to s2. s1 equals to s3. s2 equals to s4.
#include#include using namespace std;class String { private: char* p;public: String() { p = nullptr; } String(const char* s) { p = new char[strlen(s) + 1]; strcpy_s(p, strlen(s) + 1, s); } String(const String& other) { if (other.p == nullptr) { p = nullptr; } else { p = new char[strlen(other.p) + 1]; strcpy_s(p, strlen(other.p) + 1, other.p); } } void display() const { cout << p << endl; } friend bool operator==(const String& s1, const String& s2); friend bool operator<(const String& s1, const String& s2); friend bool operator>(const String& s1, const String& s2);};bool operator==(const String& s1, const String& s2) { return strcmp(s1.p, s2.p) == 0;}bool operator<(const String& s1, const String& s2) { return strcmp(s1.p, s2.p) < 0;}bool operator>(const String& s1, const String& s2) { return strcmp(s1.p, s2.p) > 0;}void main() { String s1("Hello"); String s2("World"); String s3(s1); String s4; s4 = "World"; if(s1 == s2) cout << "s1 == s2." << endl; else if (s1 < s2) cout << "s1 < s2." << endl; else if (s1 > s2) cout << "s1 > s2." << endl; if (s1 == s3) cout << "s1 == s3." << endl; else if (s1 < s3) cout << "s1 < s3." << endl; else if (s1 > s3) cout << "s1 > s3." << endl; if (s2 == s4) cout << "s1 == s4." << endl; else if (s2 < s4) cout << "s2 < s4." << endl; else if (s2 > s4) cout << "s2 > s4." << endl;}
输出结果：
s1 < s2. s1 == s3. s1 == s4.
#include#include using namespace std;const double PI = 3.1415926;class Point { protected: double x, y;public: Point(double x = 0, double y = 0) { this->x = x; this->y = y; } friend ostream& operator<<(ostream& os, const Point& p); friend istream& operator>>(istream& is, Point& p);};ostream& operator<<(ostream& os, const Point& p) { os << "(" << p.x << ", " << p.y << ")"; return os;}istream& operator>>(istream& is, Point& p) { is >> p.x >> p.y; return is;}class Circle : public Point { protected: double r;public: Circle(double x = 0, double y = 0, double r = 0) :Point(x, y) { this->r = r; } double area() const { return PI * r * r; } friend ostream& operator<<(ostream& os, const Circle& c); friend istream& operator>>(istream& is, Circle& c);};ostream& operator<<(ostream& os, const Circle& c) { os << "Center:" << (Point)c << ", Radius:" << c.r << ", Area:" << c.area(); return os;}istream& operator>>(istream& is, Circle& c) { is >> (Point&)c >> c.r; return is;}class Cylinder : public Circle { protected: double h;public: Cylinder(double x = 0, double y = 0, double r = 0, double h = 0) : Circle(x, y, r) { this->h = h; } double volume() const { return area() * h; } friend ostream& operator<<(ostream& os, const Cylinder& c); friend istream& operator>>(istream& is, Cylinder& c);};ostream& operator<<(ostream& os, const Cylinder& c) { os << "Center:" << (Point)c << " Radius:" << c.r << " Height:" << c.h << " Volume:" << c.volume(); return os;}istream& operator>>(istream& is, Cylinder& c) { is >> (Circle&)c >> c.h; return is;}int main() { Point p(1, 2); cout << p << endl; Circle c(1, 2, 3); cout << c << endl; Cylinder cy(1, 2, 3, 4); cout << cy << endl; return 0;}
输出结果：
(1, 2) Center:(1, 2), Radius:3, Area:28.2743 Center:(1, 2) Radius:3 Height:4 Volume:113.097
#include#include using namespace std;const double PI = 3.1415926;class Shape { public: virtual double area() const = 0; // 纯虚函数};class Circle: public Shape { protected: double r;public: Circle(double r = 0) { this->r = r; } double area() const { return PI * r * r; }};class Rectangle: public Shape { protected: double w, h;public: Rectangle(double w = 0, double h = 0) { this->w = w; this->h = h; } double area() const { return w * h; }};class Trapezoid: public Shape { protected: double t, b, h;public: Trapezoid(double t = 0, double b = 0, double h = 0) { this->t = t; this->b = b; this->h = h; } double area() const { return (t + b) * h / 2; }};void printArea(Shape& s) { cout << "The area is: " << s.area() << endl;}int main() { Circle c(5.0); printArea(c); Rectangle r(3.0, 4.0); printArea(r); Trapezoid t(2, 4, 5); printArea(t); return 0;}
输出结果：
The area is: 78.5398 The area is: 12 The area is: 15
#include#include using namespace std;class CPerson { protected: string name; int id; char gender;public: void input() { cout << "Enter Name: "; cin >> name; cout << "Enter ID: "; cin >> id; cout << "Enter Gender (M or F): "; cin >> gender; } void output() { cout << "Name: " << name << endl; cout << "ID: " << id << endl; cout << "Gender: " << gender << endl; }};class CStudent: public CPerson { protected: double score;public: void input() { CPerson::input(); cout << "Enter Score: "; cin >> score; } void output() { CPerson::output(); cout << "Score: " << score << endl; }};class CTeacher : public CPerson { protected: int seniority;public: void input() { CPerson::input(); cout << "Enter Seniority: "; cin >> seniority; } void output() { CPerson::output(); cout << "Seniority; " << seniority << endl; }};int main() { CStudent cs; cout << "--- input student's infomation ---" << endl; cs.input(); cout << "--- output student's infomation ---" << endl; cs.output(); CTeacher ct; cout << "--- input teacher's infomation ---" << endl; ct.input(); cout << "--- output teacher's infomation ---" << endl; ct.output(); return 0;}
输出结果：
— input student’s infomation — Enter Name: Kk Enter ID: 101 Enter Gender (M or F): M Enter Score: 100 — output student’s infomation — Name: Kk ID: 101 Gender: M Score: 100 — input teacher’s infomation — Enter Name: JJ Enter ID: 202 Enter Gender (M or F): F Enter Seniority: 20 — output teacher’s infomation — Name: JJ ID: 202 Gender: F Seniority; 20
#includeusing namespace std;class Goods { private: int weight; // 单位：克public: Goods(int w = 0) { weight = w; } int getWeight() const { return weight; }};class Store { private: Goods* inventory; // 库存商品 int size; // 库存商品数量 int capacity; // 当前最大容量public: Store(int c = 50) { capacity = c; size = 0; inventory = new Goods[c]; } ~Store() { delete[] inventory; } void addGoods(Goods g) { if (size < capacity) { inventory[size++] = g; } else { // 容量不足，需要扩容 Goods* temp = new Goods[capacity * 2]; for (int i = 0; i < capacity; i++) { temp[i] = inventory[i]; } delete[] inventory; inventory = temp; capacity = capacity * 2; inventory[size++] = g; } cout << "Add a goods with weight of " << g.getWeight() << endl; } void sellGoods(int amount) { // 出售商品 if (amount < size) { for (int i = 0; i < amount; i++) { size--; // 出售一件商品，库存-1 cout << "Sell a goods with weight of " << inventory[size].getWeight() << endl; } } else { cout << "Inventory is not enough!" << endl; } } int getInventorySize() const { // 获取当前库存量 return size; }};int main() { Store store(5); store.addGoods(Goods(100)); store.addGoods(Goods(500)); store.addGoods(Goods(300)); cout << "Current inventory: " << store.getInventorySize() << endl; store.sellGoods(2); cout << "Current inventory: " << store.getInventorySize() << endl; store.addGoods(Goods(400)); cout << "Current inventory: " << store.getInventorySize() << endl; store.sellGoods(10); return 0;}
输出结果：
Add a goods with weight of 100 Add a goods with weight of 500 Add a goods with weight of 300 Current inventory: 3 Sell a goods with weight of 300 Sell a goods with weight of 500 Current inventory: 1 Add a goods with weight of 400 Current inventory: 2 Inventory is not enough!
这里vs有个坑，就是在Time类里面直接实现函数display，会出现
还有两个地方要注意： 开头需要加上class Date; class Time在class Date上面。“Date::year”: 无法访问 private 成员(在“Date”类中声明)，后来改为外部实现才编译通过。
#include#include using namespace std;class Date;class Time { private: int hour, minute, sec;public: Time(int h = 0, int m = 0, int s = 0) : hour(h), minute(m), sec(s) { } void display(Date& d);};class Date { private: int month, day, year;public: Date(int m = 0, int d = 0, int y = 0) : month(m), day(d), year(y) { } friend void Time::display(Date& d);};void Time::display(Date& d) { cout << d.month << "/" << d.day << "/" << d.year << " "; cout << hour << ":" << minute << ":" << sec << endl;}int main() { Date d(5, 20, 2020); Time t(10, 10, 20); t.display(d); return 0;}
输出结果：
5/20/2020 10:10:20
#include#include using namespace std;class Date;class Time { private: int hour, minute, sec;public: Time(int h = 0, int m = 0, int s = 0) : hour(h), minute(m), sec(s) { } friend void display(const Date& d, const Time& t);};class Date { private: int month, day, year;public: Date(int m = 0, int d = 0, int y = 0) : month(m), day(d), year(y) { } friend void display(const Date& d, const Time& t);};void display(const Date& d, const Time& t) { cout << d.month << "/" << d.day << "/" << d.year << " "; cout << t.hour << ":" << t.minute << ":" << t.sec << endl;}int main() { Date d(5, 20, 2020); Time t(10, 10, 20); display(d, t); return 0;}
输出结果：
5/20/2020 10:10:20
#include#include using namespace std;class Point { private: double x, y;public: Point(double x = 0, double y = 0) : x(x), y(y) { } double getX() { return x; } double getY() { return y; }};class Distance { private: double dist; Point pA, pB;public: Distance(Point& p1, Point& p2): pA(p1), pB(p2) { double dx = abs(p1.getX() - p2.getX()); double dy = abs(p1.getY() - p2.getY()); dist = sqrt(dx * dx + dy * dy); } double getDist() { return dist; }};int main() { Point p1(0, 0); Point p2(3, 4); Distance d(p1, p2); cout << "The distance between p1 and p2 is " << d.getDist() << endl; return 0;}
输出结果：
The distance between p1 and p2 is 5
#include#include using namespace std;class Point { private: double x, y;public: Point(double x = 0, double y = 0) : x(x), y(y) { } double getX() { return x; } double getY() { return y; } friend double Distance(Point& p1, Point& p2);};double Distance(Point& p1, Point& p2) { double dx = abs(p1.x - p2.x); double dy = abs(p1.y - p2.y); return sqrt(dx * dx + dy * dy);}int main() { Point p1(0, 0); Point p2(3, 4); cout << "The distance between p1 and p2 is " << Distance(p1, p2) << endl; return 0;}
输出结果：
The distance between p1 and p2 is 5
#include#include using namespace std;template class Double { private: numtype x;public: Double(numtype x):x(x){ } numtype doubleValue() { return 2 * x; }};int main() { Double d1(10); cout << "The double of 10 is " << d1.doubleValue() << endl; Double d2(10.55); cout << "The double of 10.55 is " << d2.doubleValue() << endl; Double d3(20.3333); cout << "The double of 20.3333 is " << d3.doubleValue() << endl; return 0;}
输出结果：
The double of 10 is 20 The double of 10.55 is 21.1 The double of 20.333333 is 40.6666
这里为了实现每秒输出一次，引用了头文件window.h，Sleep(1000)表示休眠1000ms
引用头文件iomanip，setw(2)设置宽度为2，setfill(‘0’)设置填充’0’ 实际练习可以忽略
#include#include #include using namespace std;class Time { private: int minute, sec;public: Time(int m = 0, int s = 0) : minute(m), sec(s) { } void run() { while (true) { cout << "Current time:" << setw(2) << setfill('0') << minute; cout << ":" << setw(2) << setfill('0') << sec << endl; sec++; if (sec >= 60) { sec = 0; minute++; } if(minute >= 60) { minute = 0; } Sleep(1000); } }};int main() { Time t(59, 55); t.run(); return 0;}
输出结果：
Current time:59:55 Current time:59:56 Current time:59:57 Current time:59:58 Current time:59:59 Current time:00:00 Current time:00:01 Current time:00:02 Current time:00:03 Current time:00:04 Current time:00:05 …
#includeusing namespace std;class Complex { private: double real; // 实部 double imag; // 虚部public: Complex(double r = 0, double i = 0) : real(r), imag(i) { } // 成员函数方式重载运算符“-” Complex operator-(const Complex& other) const { return Complex(real - other.real, imag - other.imag); } // 友元函数方式重载运算符“-” friend Complex operator-(double d, const Complex& c) { return Complex(d - c.real, -c.imag); } // 友元函数方式重载输出运算符“<<” friend ostream& operator<<(ostream& os, const Complex& c) { os << "(" << c.real << ", " << c.imag << ")"; return os; }};int main() { Complex a(3, 4); Complex b(1, 2); // 使用成员函数方式重载的减法运算符 Complex c1 = a - b; cout << "c1 = a - b = " << c1 << endl; // 使用友元函数方式重载的减法运算符 double d = 5.0; Complex c2 = d - b; cout << "c2 = " << d << " - b = " << c2 << endl; return 0;}
输出结果：
c1 = a - b = (2, 2) c2 = 5 - b = (4, -2)
#includeusing namespace std;class Product { private: static double discount; // 折扣 static double sum; // 总销售款 static int n; // 总销售数 int num; // 销售员号 int quantity; // 销售件数 double price; // 销售单价public: Product(int n, int q, double p) :num(n), quantity(q), price(p) { } void sale() { double total = quantity * price; if (quantity > 10) { total *= discount; } sum += total; n += quantity; } static double average() { return sum / n; } static void display() { cout << "The total sales amount is " << sum; cout << ", and average is " << average() << endl; }};double Product::discount = 0.98;double Product::sum = 0;int Product::n = 0;int main() { Product p1(101, 5, 23.5); Product p2(102, 12, 24.56); Product p3(104, 100, 21.5); p1.sale(); p2.sale(); p3.sale(); Product::display(); return 0;}
输出结果：
The total sales amount is 2513.33, and average is 21.4814
后置自增运算符：Time& operator(int);
前置自增运算符：Time& operator();
#includeusing namespace std;class Time { private: int minute; int sec;public: Time(int m = 0, int s = 0) : minute(m), sec(s) { } void display() { cout << "time: " << minute << ":" << sec << endl; } Time& operator++(int) { // Time++ sec++; if (sec >= 60) { minute += sec / 60; sec %= 60; } return *this; } Time& operator++() { // ++Time sec++; if (sec >= 60) { minute += sec / 60; sec %= 60; } return *this; }};int main() { Time t(6, 50); t.display(); // 输出当前时间 t++; // 模拟时间流逝，自增1秒 t.display(); // 输出当前时间 ++t; // 模拟时间流逝，自增1秒 t.display(); // 输出当前时间 return 0;}
输出结果：
time: 6:50 time: 6:51 time: 6:52
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