运算符重载

运算符重载

operator+()函数的名称使得可以使用函数表达法和运算符表示符表示法来调用它。编译器将根据操作类的类型来确定如何做：

 int a,b,c;
 TIME A,B,C,D;
 c=a+b;
 C=A+B;
 C=A+B+D+C;

#include<iostream>
using namespace std;
class TIME
{
public:
	TIME();
	TIME(int a,int b=0);
	~TIME();
	void addmin(int t1);
	void addhou(int t2);
	TIME operator+(const TIME& t3)const;
	TIME operator*(double t6)const;
	void show();
private:
	int h;
	int m;
};
TIME TIME::operator*(double t6)const
{
	TIME f;
	long s = h * t6 * 60 + m*t6;
	f.h = s / 60;
	f.m = s %60;
	return f;
}
TIME TIME::operator+(const TIME& t3)const
{
 
	TIME t4;
	t4.m = t3.m + m;
	t4.h = t3.h + m / 60+h;
	t4.m = t4.m % 60;
 
	return t4;
}
 
void TIME::show()
{
	cout << "minutes:" << m << endl << "hours:" << h << endl;
}
void TIME::addmin(int t1)
{
	m = m + t1;
	h = h + m / 60;
	m = m % 60;
}
void TIME::addhou(int t2)
{
	h = h + t2;
}
TIME::TIME()
{
	h = 0;
	m = 0;
 
}
TIME::TIME(int a,int b)
{
	h = a;
	m = b;
}
 
TIME::~TIME()
{
}
int main()
{
	TIME m1;
	TIME m2(2, 30);
	TIME m3;
	TIME m4;
	TIME m5;
	TIME m6;
 
	m1.addmin(68);
	m1.show();
 
	m3 = m2+m1;
	m3.show();
	m4 = m2 + m1 + m1;
	m4.show();
	m5 = m4.operator*(2);
	m5.show();
	m6 = m4 * 2;
	m6.show();
 
	return 0;
}

在这里m4*&2不等于2*m4，下面友元会将。