22 完善的复数类

目录

• 复数类应该具有的操作

  • 运算：+，-，*，/
  • 比较：==，!=
  • 赋值：=
  • 求模：modulus

• 利用操作符重载

  • 统一复数与实数的运算方式
  • 统一复数与实数的比较方式

  Complex operator + (const Complex& c);
  Complex operator - (const Complex& c);
  Complex operator * (const Complex& c);
  Complex operator / (const Complex& c);
  
  bool operator == (const Complex& c);
  bool operator != (const Complex& c);
  
  Complex& operator = (const Complex& c);
  

• 示例：复数类的实现

  • Demo

    //Complex.h
    #ifndef _COMPLEX_H_
    #define _COMPLEX_H_
    
    class Complex
    {
        double a;
        double b;
    public:
        Complex(double a = 0, double b = 0);
        double getA();
        double getB();
        double getModulus();
        
        Complex operator + (const Complex& c);
        Complex operator - (const Complex& c);
        Complex operator * (const Complex& c);
        Complex operator / (const Complex& c);
        
        bool operator == (const Complex& c);
        bool operator != (const Complex& c);
        
        Complex& operator = (const Complex& c);
    };
    
    #endif
    
    
    //Complex.cpp
    #include "Complex.h"
    #include "math.h"
    
    Complex::Complex(double a, double b)
    {
        this->a = a;
        this->b = b;
    }
    
    double Complex::getA()
    {
        return a;
    }
    
    double Complex::getB()
    {
        return b;
    }
    
    double Complex::getModulus()
    {
        return sqrt(a * a + b * b);
    }
    
    Complex Complex::operator + (const Complex& c)
    {
        double na = a + c.a;
        double nb = b + c.b;
        Complex ret(na, nb);
        
        return ret;
    }
    
    Complex Complex::operator - (const Complex& c)
    {
        double na = a - c.a;
        double nb = b - c.b;
        Complex ret(na, nb);
        
        return ret;
    }
    
    Complex Complex::operator * (const Complex& c)
    {
        double na = a * c.a - b * c.b;
        double nb = a * c.b + b * c.a;
        Complex ret(na, nb);
        
        return ret;
    }
    
    Complex Complex::operator / (const Complex& c)
    {
        double cm = c.a * c.a + c.b * c.b;
        double na = (a * c.a + b * c.b) / cm;
        double nb = (b * c.a - a * c.b) / cm;
        Complex ret(na, nb);
        
        return ret;
    }
        
    bool Complex::operator == (const Complex& c)
    {
        return (a == c.a) && (b == c.b);
    }
    
    bool Complex::operator != (const Complex& c)
    {
        return !(*this == c);
    }
        
    Complex& Complex::operator = (const Complex& c)
    {
        if( this != &c )
        {
            a = c.a;
            b = c.b;
        }
        
        return *this;
    }
    

• 注意事项

  • C++ 规定赋值操作符（=）只能重载为成员函数
  • 操作符重载不能改变原操作符的优先级
  • 操作符重载不能改变操作数的个数
  • 操作符重载不应改变操作符的原有语义