操作符重载02--运算操作符（Arithmetic Operators）

测试类.h

#pragma once

/*运算操作符重载
1. 运算操作符为2元操作符
2. 一般使用友元friend的形式，友元可以访问任何权限的成员变量，如果使用成员函数的形式，
   则只带一个参数，还有一个为本身，友元带2个参数，运算结果直接返回，使用方便
3. 注意要满足运算符有意义，尤其是除法
*/
class TRectangle
{
    friend TRectangle operator+(const TRectangle& x, const TRectangle& y);
    friend TRectangle operator-(const TRectangle& x, const TRectangle& y);
    friend TRectangle operator*(const TRectangle& x, const TRectangle& y);
    friend TRectangle operator/(const TRectangle& x, const TRectangle& y);
public:
    TRectangle(double L = 0.00, double H = 0.00);
    TRectangle(const TRectangle& R);
    ~TRectangle();

    //method
    void setLength(const double L) { Length = L; }
    double getLength() const { return Length; }
    void setHeight(const double H) { Height = H; }
    double getHeight() const { return Height; }
    double Perimeter() const { return 2 * (Length + Height); }
    double Area() const { return Length * Height; }

    TRectangle& operator=(const TRectangle& Rect);
private:
    double Length;
    double Height;
};

测试类.cpp

#include "StdAfx.h"
#include "TRectangle.h"


TRectangle::TRectangle(double L, double H) :
Length(L),
Height(H)
{
}

TRectangle::TRectangle(const TRectangle& R) :
Length(R.Length),
Height(R.Height)
{
}

TRectangle::~TRectangle(void)
{
}

TRectangle& TRectangle::operator=(const TRectangle& Rect)
{
    Length = Rect.Length;
    Height = Rect.Height;
    return *this;
}

TRectangle operator+(const TRectangle& x, const TRectangle& y)
{
    TRectangle R;
    R.Length = x.Length + y.Length;
    R.Height = x.Height + y.Height;
    return R;
}

TRectangle operator-(const TRectangle& x, const TRectangle& y)
{
    TRectangle R;
    R.Length = x.Length - y.Length;
    R.Height = x.Height - y.Height;

    return R;
}

TRectangle operator*(const TRectangle& x, const TRectangle& y)
{
    TRectangle R;
    R.Length = x.Length * y.Length;
    R.Height = x.Height * y.Height;

    return R;
}

TRectangle operator/(const TRectangle& x, const TRectangle& y)
{
    TRectangle R;
    if( y.Length == 0 ) // 避免分母为0
        R.Length = 0;
    else
        R.Length = x.Length / y.Length;

    if( y.Height == 0 )
        R.Height = 0;
    else
        R.Height = x.Height / y.Height;

    return R;
}

main()

// ArithmeticOperators.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "TRectangle.h"
#include <iostream>
using namespace std;

void ShowResult(TRectangle& R)
{
    cout << "Length : " << R.getLength() << " Height : " << R.getHeight() << endl;
}

int _tmain(int argc, _TCHAR* argv[])
{
    TRectangle Ra, Rb, Rc;
    Ra.setLength(20);
    Ra.setHeight(10);

    Rb.setLength(40);
    Rb.setHeight(20);

    ShowResult(Ra);
    ShowResult(Rb);

    Rc = Ra + Rb;
    ShowResult(Rc);

    Rc = Ra - Rb;
    ShowResult(Rc);

    Rc = Ra * Rb;
    ShowResult(Rc);

    Rc = Ra / Rb;
    ShowResult(Rc);
    return 0;
}

 

测试结果图：