# Complex Numbers Class

Introduction

This small example demonstrates using some of the interesting language elements of the C# language. Probably the most interesting is operator overloading - a feature that shouldn't be overused, but in this example the using is appropriate. Further an override of the ToString() method and attribute using are demonstrated as well. The attribute [Description] is used instead of simple comments, which can be used when referencing the component.

Source Code

namespace PROINFO.Math.Complex
{
using System;
using System.ComponentModel;
using System.Diagnostics;
public class Complex
{
[Description("Constructor")]
public Complex(double re, double im)
{
this.re = re;
this.im = im;
}
public static Complex operator +(Complex arg1, Complex arg2)
{
return (new Complex(arg1.re + arg2.re, arg1.im + arg2.im));
}
public static Complex operator -(Complex arg1)
{
return (new Complex(-arg1.re, -arg1.im));
}
public static Complex operator -(Complex arg1, Complex arg2)
{
return (new Complex(arg1.re - arg2.re, arg1.im - arg2.im));
}
public static Complex operator *(Complex arg1, Complex arg2)
{
return (new Complex(arg1.re * arg2.re - arg1.im * arg2.im, arg1.re * arg2.im + arg2.re * arg1.im));
}
public static Complex operator /(Complex arg1, Complex arg2)
{
double c1, c2, d;
d = arg2.re * arg2.re + arg2.im * arg2.im;
if (d == 0)
{
return (new Complex(0, 0));
}
c1 = arg1.re * arg2.re + arg1.im * arg2.im;
c2 = arg1.im * arg2.re - arg1.re * arg2.im;
return (new Complex(c1 / d, c2 / d));
}
[Description("Absolute value of a complex number. Usage: c.Abs()")]
public double Abs()
{
return (Math.Sqrt(re * re + im * im));
}
[Description("Argument of a complex number in degree. Usage: c.Arg()")]
public double Arg()
{
double ret = 0;
if (re != 0)
ret = (180 / Math.PI) * Math.Atan(im / re);
return (ret);
}
[Description("Overridden ToString. Usage: c.toString()")]
public override string ToString()
{
return (String.Format("Complex: ({0}, {1})", re, im));
}
// private members
private double re;
private double im;
}
public class Test
{
public static void Main()
{
Complex c1 =
new Complex(3, 3);
Complex c2 =
new Complex(2, 4);
Complex c3 =
new Complex(0, 0);
Debug.WriteLine(c1 + c2);
Debug.WriteLine(c1 - c2);
Debug.WriteLine(c1 * c2);
Debug.WriteLine(c1 / c2);
Debug.WriteLine(c1 + c3);
Debug.WriteLine(c1 - c3);
Debug.WriteLine(c1 * c3);
Debug.WriteLine(c1 / c3);
Debug.WriteLine(c1.Abs());
Debug.WriteLine(c1.Arg());
Debug.WriteLine(c2.Abs());
Debug.WriteLine(c2.Arg());
Debug.WriteLine(c3.Abs());
Debug.WriteLine(c3.Arg());
}
}
}

Up Next