操作符重载04--布尔（逻辑）操作符（Boolean Operators）

测试类.h

   1: #pragma once

   2:  

   3: /*布尔（逻辑）操作符重载

   4: 1. 布尔操作符为2元操作符

   5: 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，

   6:    则只带一个参数，还有一个为本身，友元带2个参数

   7: */

   8: class TRectangle

   9: {

  10:     friend TRectangle operator+(const TRectangle& x, const TRectangle& y);

  11:     friend TRectangle operator-(const TRectangle& x, const TRectangle& y);

  12:     friend TRectangle operator*(const TRectangle& x, const TRectangle& y);

  13:     friend TRectangle operator/(const TRectangle& x, const TRectangle& y);

  14:  

  15:     //boolean operators

  16:     friend bool operator==(const TRectangle& x, const TRectangle& y);

  17:     friend bool operator!=(const TRectangle& x, const TRectangle& y);

  18:     friend bool operator<(const TRectangle& x, const TRectangle& y);

  19:     friend bool operator<=(const TRectangle& x, const TRectangle& y);

  20:     friend bool operator>(const TRectangle& x, const TRectangle& y);

  21:     friend bool operator>=(const TRectangle& x, const TRectangle& y);

  22: public:

  23:     TRectangle(double L = 0.00, double H = 0.00);

  24:     TRectangle(const TRectangle& R);

  25:     ~TRectangle();

  26:  

  27:     //method

  28:     void setLength(const double L) { Length = L; }

  29:     double getLength() const { return Length; }

  30:     void setHeight(const double H) { Height = H; }

  31:     double getHeight() const { return Height; }

  32:     double Perimeter() const { return 2 * (Length + Height); }

  33:     double Area() const { return Length * Height; }

  34:  

  35:     TRectangle& operator=(const TRectangle& Rect);

  36: private:

  37:     double Length;

  38:     double Height;

  39: };

  40:  

测试类.cpp

   1: #include "StdAfx.h"

   2: #include "TRectangle.h"

   3:  

   4:  

   5: TRectangle::TRectangle(double L, double H) : 

   6: Length(L),

   7: Height(H)

   8: {

   9: }

  10:  

  11: TRectangle::TRectangle(const TRectangle& R) :

  12: Length(R.Length),

  13: Height(R.Height)

  14: {

  15: }

  16:  

  17: TRectangle::~TRectangle(void)

  18: {

  19: }

  20:  

  21: TRectangle& TRectangle::operator=(const TRectangle& Rect)

  22: {

  23:     Length = Rect.Length;

  24:     Height = Rect.Height;

  25:     return *this;

  26: }

  27:  

  28: TRectangle operator+(const TRectangle& x, const TRectangle& y)

  29: {

  30:     TRectangle R;

  31:     R.Length = x.Length + y.Length;

  32:     R.Height = x.Height + y.Height;

  33:     return R;

  34: }

  35:  

  36: TRectangle operator-(const TRectangle& x, const TRectangle& y)

  37: {

  38:     TRectangle R;

  39:     R.Length = x.Length - y.Length;

  40:     R.Height = x.Height - y.Height;

  41:  

  42:     return R;

  43: }

  44:  

  45: TRectangle operator*(const TRectangle& x, const TRectangle& y)

  46: {

  47:     TRectangle R;

  48:     R.Length = x.Length * y.Length;

  49:     R.Height = x.Height * y.Height;

  50:  

  51:     return R;

  52: }

  53:  

  54: TRectangle operator/(const TRectangle& x, const TRectangle& y)

  55: {

  56:     TRectangle R;

  57:     if( y.Length == 0 ) // 避免分母为0

  58:         R.Length = 0;

  59:     else

  60:         R.Length = x.Length / y.Length;

  61:  

  62:     if( y.Height == 0 )

  63:         R.Height = 0;

  64:     else

  65:         R.Height = x.Height / y.Height;

  66:  

  67:     return R;

  68: }

  69:  

  70: bool operator==(const TRectangle& x, const TRectangle& y)

  71: {

  72:     if( x.Area() == y.Area() )

  73:         return true;

  74:     return false;

  75: }

  76:  

  77: bool operator!=(const TRectangle& x, const TRectangle& y)

  78: {

  79:     if( x.Area() != y.Area() )

  80:         return true;

  81:     return false;

  82: }

  83:  

  84: bool operator<(const TRectangle& x, const TRectangle& y)

  85: {

  86:     if( x.Area() < y.Area() )

  87:         return true;

  88:     return false;

  89: }

  90:  

  91: bool operator<=(const TRectangle& x, const TRectangle& y)

  92: {

  93:     if( x.Area() <= y.Area() )

  94:         return true;

  95:     return false;

  96: }

  97:  

  98: bool operator>(const TRectangle& x, const TRectangle& y)

  99: {

 100:     if( x.Area() > y.Area() )

 101:         return true;

 102:     return false;

 103: }

 104:  

 105: bool operator>=(const TRectangle& x, const TRectangle& y)

 106: {

 107:     if( x.Area() >= y.Area() )

 108:         return true;

 109:     return false;

 110: }

main

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

   2: //

   3:  

   4: #include "stdafx.h"

   5: #include "TRectangle.h"

   6: #include <iostream>

   7: using namespace std;

   8:  

   9: int _tmain(int argc, _TCHAR* argv[])

  10: {

  11:     TRectangle Ra(10, 20), Rb(11,21);

  12:     if(Ra > Rb)

  13:         cout << "Ra 大于 Rb" << endl; 

  14:     else if(Ra == Rb)

  15:         cout << "Ra 等于 Rb" << endl;

  16:     else

  17:         cout << "Ra 小于 Rb" << endl;

  18:     return 0;

  19: }

  20:  

测试结果图

转载于:https://www.cnblogs.com/maogeblog/archive/2012/09/14/2685848.html