一些简单的操作符重载

<pre name="code" class="cpp">#include <iostream>
using namespace std;
class MyInt {
int nVal;
public:
MyInt(int n) { nVal = n; }
int ReturnVal() { return nVal; }
// 在此处补充你的代码
MyInt & operator -(int n)
{
nVal -= n;
return *this;
}
};
int main () {
MyInt objInt(10);
objInt-2-1-3;
cout << objInt.ReturnVal();
cout <<",";
objInt-2-1;
cout << objInt.ReturnVal();
return 0;
}

#include <iostream>
#include <cstring>
#include <cstdlib>
#include<sstream>
using namespace std;
class Complex
{
private:
double r,i;
public:
Complex(double r, double i)
{ this->r = r; this->i = i;}
//写了有参的构造函数就得写无参的。
Complex(){ this->r = 0; this->i = 0;}
double getReal() { return r;}
double getImaginary(){return i;}
void setReal(double r){this->r=r;}
void setImaginary(double i){this->i = i;}
//用sstream有点作弊的感觉，有什么其他方法？
void operator = (const char * c){stringstream a;int sr,si;char x,y;a<<c;a>>sr>>x>>si>>y;r=sr;i=si;if(x=='-')i=-i;}
//完成c=a+b；
Complex operator+ (Complex & b){return Complex(r+b.r,i+b.i);}
//减法也差不多
Complex operator- (Complex & b){return Complex(r-b.r,i-b.i);}
//乘法 c=a*b;
Complex operator* (Complex & b){return Complex(r * b.r - i * b.i, r * b.i + i * b.r);}
//除法 略。
//判断的
bool operator== (Complex & b){if(r == b.r || i == b.i)return true;else return false;}
bool operator!= (Complex & b){if((*this)== b) return false;else return true;}
//复数比较大小用绝对值 };//cout<<a;来代替print,把他设为全局函数 ,因为otream已经写好了，不能再添加成员函数
/*void Print() { cout << r << "+" << i << "i" << endl; }*/
ostream & operator<< (ostream & o, Complex & c) {o<< c.getReal() ;double i=c.getImaginary();if(i>0) o << "+" << i << "i" ;if(i<0) o <<i<<"i";return o;}
//现在来完成cin>>b; 从键盘输入 5+6i
istream & operator>>(istream & in, Complex & c)
{stringstream a;string b;in>>b;a<<b;double r,i;char x, y;a>>r>>x>>i>>y;c.setReal(r);if(x=='-') c.setImaginary(-i);else c.setImaginary(i);}
//还是用了sstream，明显不是最佳方法。