Overload != operator : Operator Overloading « Class Interface « C# / C Sharp

1. C# / C Sharp
2. Class Interface
3. Operator Overloading

Overload != operator

/*
Learning C# 
by Jesse Liberty

Publisher: O'Reilly 
ISBN: 0596003765
*/
 using System;

 class Fraction
 {
     private int numerator;
     private int denominator;

     // create a fraction by passing in the numerator
     // and denominator
     public Fraction(int numerator, int denominator)
     {
         this.numerator=numerator;
         this.denominator=denominator;
     }

     // overload the constructor to create a
     // fraction from a whole number
     public Fraction(int wholeNumber)
     {
         Console.WriteLine("In constructor taking a whole number");
         numerator = wholeNumber;
         denominator = 1;
     }

     // convert ints to Fractions implicitly
     public static implicit operator Fraction(int theInt)
     {
         Console.WriteLine("Implicitly converting int to Fraction");
         return new Fraction(theInt);
     }

     // convert Fractions to ints explicitly
     public static explicit operator int(Fraction theFraction)
     {
         Console.WriteLine("Explicitly converting Fraction to int");
         return theFraction.numerator /
             theFraction.denominator;
     }


     // overloaded operator + takes two fractions
     // and returns their sum
     public static Fraction operator+(Fraction lhs, Fraction rhs)
     {
         // like fractions (shared denominator) can be added
         // by adding thier numerators
         if (lhs.denominator == rhs.denominator)
         {
             return new Fraction(lhs.numerator+rhs.numerator,
                 lhs.denominator);
         }

         // simplistic solution for unlike fractions
         // 1/2 + 3/4 == (1*4) + (3*2) / (2*4) == 10/8
         // this method does not reduce.
         int firstProduct = lhs.numerator * rhs.denominator;
         int secondProduct = rhs.numerator * lhs.denominator;
         return new Fraction(
             firstProduct + secondProduct,
             lhs.denominator * rhs.denominator
             );
     }

     // test whether two Fractions are equal
     public static bool operator==(Fraction lhs, Fraction rhs)
     {
         if (lhs.denominator == rhs.denominator &&
             lhs.numerator == rhs.numerator)
         {
             return true;
         }
         // code here to handle unlike fractions
         return false;
     }

     // delegates to operator ==
     public static bool operator !=(Fraction lhs, Fraction rhs)
     {
         bool equality = lhs==rhs;
         return !(equality);
     }

     // tests for same types, then delegates
     public override bool Equals(object o)
     {
         if (! (o is Fraction) )
         {
             return false;
         }
         return this == (Fraction) o;
     }

     // return a string representation of the fraction
     public override string ToString()
     {
         String s = numerator.ToString() + "/" +
             denominator.ToString();
         return s;
     }


 }


 public class TesterOverrideThree
 {
     static void Main()
     {
         Fraction f1 = new Fraction(3,4);
         Fraction f2 = new Fraction(2,4);
         Fraction f3 = f1 + f2;

         Console.WriteLine("adding f3 + 5...");
         Fraction f4 = f3 + 5;
         Console.WriteLine("f3 + 5 = f4: {0}", f4.ToString());

         Console.WriteLine("\nAssigning f4 to an int...");
         int truncated = (int) f4;
         Console.WriteLine("When you truncate f4 you get {0}",
             truncated);
     }
 }

           
       

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