Perfect complex class

• Operation that complex class should have

  • Operation: +, -, */
  • Comparison: = ==
  • Assignment: =
  • Modulus: modulus

• Using operator overloading

  • Unified operation of complex number and real number
  • The comparison of unified complex number and real number

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);

Programming experiment: the realization of complex class

Complex.h

#ifndef _COMPLEX_H_
#define _COMPLEX_H_

class Complex
{
private:
    double a;
    double b;

public:
    Complex(int a = 0, int b = 0);
    int getA();
    int getB();
    int 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(int a, int b)
{
    this->a = a;
    this->b = b;
}

int Complex::getA()
{
    return a;
}

int Complex::getB()
{
    return b;
}

int Complex::getModulus()
{
    return sqrt(a * a + b * b);
}

Complex Complex::operator + (const Complex& c)
{
    double na = a + c.a;
    double nb = b + c.a;
    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 nm = c.a * c.a + c.b * c.b;
    double na = (a * c.a + b * c.b) / nm;
    double nb = (b * c.a - a * c.b) / nm;
    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);
}

// In order to implement circular assignment, return the self reference
Complex& Complex::operator = (const Complex& c)
{
    // Skip if you intend to assign a value to yourself
    if( this != &c )
    {
        a = c.a;
        b = c.b;
    }
    
    return *this;
}

main.cpp

#include <stdio.h>
#include "Complex.h"

int main()
{
    Complex c1(1, 2);
    Complex c2(3, 6);
    Complex c3 = c2 - c1;
    Complex c4 = c2 + c1;
    Complex c5 = c2 * c1;
    Complex c6 = c2 / c1;
    
    printf("c3.a = %d, c3.b = %d\n", c3.getA(), c3.getB());
    printf("c4.a = %d, c4.b = %d\n", c4.getA(), c4.getB());
    printf("c5.a = %d, c5.b = %d\n", c5.getA(), c5.getB());
    printf("c6.a = %d, c6.b = %d\n", c6.getA(), c6.getB());

    Complex c7(1, 2);
    
    printf("c1 == c7 : %d\n", c1 == c7);
    printf("c2 != c7 : %d\n", c2 != c7);

    (c3 = c2) = c1;
    
    printf("c1.a = %d, c1.b = %d\n", c1.getA(), c1.getB());
    printf("c2.a = %d, c2.b = %d\n", c2.getA(), c2.getB());
    printf("c3.a = %d, c3.b = %d\n", c3.getA(), c3.getB());
    

    return 0;
}

Output:
c3.a = 2, c3.b = 4
c4.a = 4, c4.b = 7
c5.a = -9, c5.b = 12
c6.a = 3, c6.b = 0
c1 == c7 : 1
c2 != c7 : 1
c1.a = 1, c1.b = 2
c2.a = 3, c2.b = 6
c3.a = 1, c3.b = 2

Matters needing attention

• C + + specifies that the assignment operator (= =) can only be overloaded as a member function
• Operator overloading cannot change the priority of the original operator
• Operators cannot change the number of operands
• Operators should not change their original semantics

Summary

• The concept of complex number can be realized by custom class
• Operators in complex numbers can be implemented by operator overloading
• Assignment operators can only be implemented through member functions
• The essence of operator overloading is function definition

The above contents refer to the series courses of Ditai Software Institute, please protect the original!