【Tips】C++语言程序设计

【Tips】C++语言程序设计

@运算符重载

#include 
using namespace std;

class Complex {
public:
	Complex(double r = 0.0, double i = 0.0):real(r),imag(i) {}
	Complex operator+ (const Complex &c2) const;
	Complex oeprator- (const Complex &c2) const;
	void display() const;
private:
	double real;
	double imag;
};

Complex Complex::operator+ (const Complex &c2) const {
	return Complex(real+c2.real, imag+c2.imag);
}

Complex Complex::operator- (const Complex &c2) const {
	return Complex(real-c2.real, imag-c2.imag);
}

void Complex::display() const {
	std::cout << "(" << real << ", " << imag << ")" << std::endl;
}

int main() {
	Complex c1(5, 4), c2(2, 10), c3;
	std::cout << "c1=";c1.display();
	std::cout << "c2=";c2.diaplay();
	c3=c1-c2;
	std::cout << "c3=c1+c2=";c3.display();
	
	return 0;
} 

@将单目运算符++重载为成员函数。

#include 
using namespace std;
class Clock {
public:
	Clock(int hour=0, int minute=0, int second=0);
	void showTime() const;
	Clock& operator++();
	Clock& operator++(int);
private:
	int hour, minute, second;
};

Clock::Clock(int hour, int minute, int second) {
	this->hour = hour;
	this->minute = minute;
	this->second = second;
}

void Clock::showTime() {
	std::cout << hour << ":" << minute << ":" << second << std::endl;
}

Clock& Clock::operator++ () {
	second++;
	if(second>=60) {
		second-=60;
		minute++;
		if(minute>=60) {
			minute-=60;
			hour=(hour+1)%24;
		}
	}
	return *this;
}

Clock Clock::operator++(this) {
	Clock old = *this;
	++(*this);
	return old;
}

int main() {
	Clock myClock(23, 59, 59);
	std::cout << "Fist time output: ";
	myClock.showTime();
	std::cout << "Show myClock++: ";
	(myClock++).showTime();
	std::cout << "Show++myClock: ";
	(++myClock).showTime();
	
	return 0;
}

@以非成员函数形式重载运算符