C# Exercise 6

Objective:

• Operator Overloading

Activity 1:

Write a class called Fraction that represents a fraction (i.e., a rational number). Overload the +, -, *, and / operators to allow addition, subtraction, multiplication, and division of two fractions. The class should also implement a method called Simplify() that simplifies the fraction to lowest terms. The class should have the following attributes: numerator (the numerator of the fraction) and denominator (the denominator of the fraction).

Solution:

using System;

class Fraction
{
    private int numerator;
    private int denominator;

    public Fraction(int n = 0, int d = 1)
    {
        if (d == 0)
        {
            Console.WriteLine("Error: Division by zero");
            return;
        }
        numerator = n;
        denominator = d;
    }

    private int GCD(int a, int b)
    {
        return b == 0 ? a : GCD(b, a % b);
    }

    public void Simplify()
    {
        int g = GCD(numerator, denominator);
        numerator /= g;
        denominator /= g;
    }

    public static Fraction operator +(Fraction a, Fraction b)
    {
        int n = a.numerator * b.denominator + b.numerator * a.denominator;
        int d = a.denominator * b.denominator;
        return new Fraction(n, d);
    }

    public static Fraction operator -(Fraction a, Fraction b)
    {
        int n = a.numerator * b.denominator - b.numerator * a.denominator;
        int d = a.denominator * b.denominator;
        return new Fraction(n, d);
    }

    public static Fraction operator *(Fraction a, Fraction b)
    {
        int n = a.numerator * b.numerator;
        int d = a.denominator * b.denominator;
        return new Fraction(n, d);
    }

    public static Fraction operator /(Fraction a, Fraction b)
    {
        if (b.numerator == 0)
        {
            Console.WriteLine("Error: Division by zero");
            return new Fraction();
        }
        int n = a.numerator * b.denominator;
        int d = a.denominator * b.numerator;
        return new Fraction(n, d);
    }

    public void Print()
    {
        Console.WriteLine($"{numerator}/{denominator}");
    }
}

class Program
{
    static void Main()
    {
        Console.WriteLine("f1(1, 2) and f2(2, 3).");
        Fraction f1 = new Fraction(1, 2);
        Fraction f2 = new Fraction(2, 3);
        Fraction f3 = f1 + f2;
        Fraction f4 = f1 - f2;
        Fraction f5 = f1 * f2;
        Fraction f6 = f1 / f2;
        f3.Simplify();
        f4.Simplify();
        f5.Simplify();
        f6.Simplify();
        f3.Print();
        f4.Print();
        f5.Print();
        f6.Print();
    }
}

Activity 2:

Write a class called ComplexNumber that represents a complex number. Overload the ++ and -- operators to allow incrementing and decrementing the real and imaginary parts of the complex number. The class should have the following attributes: real (the real part of the complex number) and imag (the imaginary part of the complex number).

Solution:

using System;

class ComplexNumber
{
    public double real;
    public double imag;

    public ComplexNumber(double r, double i)
    {
        real = r;
        imag = i;
    }

    public static ComplexNumber operator ++(ComplexNumber a)
    {
        a.real++;
        a.imag++;
        return a;
    }

    public static ComplexNumber operator --(ComplexNumber a)
    {
        a.real--;
        a.imag--;
        return a;
    }
}

class Program
{
    static void Main()
    {
        ComplexNumber c = new ComplexNumber(1, 2);
        c++;
        Console.WriteLine($"{c.real} {c.imag}");
        c--;
        Console.WriteLine($"{c.real} {c.imag}");
    }
}

Activity 3: 

Write a class called String that represents a string. Overload the + operator to allow concatenation of two strings. The class should also implement a method called reverse() that reverses the string. The class should have the following attribute: str (the string).

Solution:

using System;

class String
{
    public string str;

    public String()
    {
        str = "";
    }

    public String(string s)
    {
        str = s;
    }

    public static String operator +(String s1, String s2)
    {
        return new String(s1.str + s2.str);
    }

    public void Reverse()
    {
        char[] charArray = str.ToCharArray();
        Array.Reverse(charArray);
        str = new string(charArray);
    }
}

class Program
{
    static void Main()
    {
        Console.WriteLine("s1(Hello) and s2(World).");
        String s1 = new String("Hello");
        String s2 = new String("World");

        String s3 = s1 + s2;
        Console.WriteLine(s3.str);

        s3.Reverse();
        Console.WriteLine(s3.str);
    }
}