源程序：
//"+"、"-"运算符重载
#include <iostream>
using namespace std;
class myComplex
{
private:
double real, imag;
public:
myComplex();
myComplex(double x, double i);
void outCom();
myComplex operator-(const myComplex &c);
friend myComplex operator+(const myComplex &c1, const myComplex &c2);//声明友元函数
};
myComplex::myComplex()
{
real = 0;
imag = 0;
}
myComplex::myComplex(double r, double i)
{
real = r;
imag = i;
}
void myComplex::outCom()
{
cout << "(" << real << "," << imag << ")";
}
myComplex myComplex::operator-(const myComplex &c)
{
return myComplex(this->real - c.real, this->imag - c.imag);
}
myComplex operator+(const myComplex &c1, const myComplex &c2)//友元函数可以直接在类外定义
{
return myComplex(c1.real + c2.real, c1.imag + c2.imag);
}
int main()
{
myComplex c1(1,2), c2(3,4),res;
c1.outCom();
cout << "operator+";
c2.outCom();
cout << "=";
res = c1 + c2;
res.outCom();
cout << endl;
c1.outCom();
cout << "operator-";
c2.outCom();
cout << "=";
res = c1 - c2;
res.outCom();
cout << endl;
system("pause");
return 1;
}
运行结果：
来源：https://www.cnblogs.com/duanqibo/p/12059875.html