Bevan Rudge JavaScript and web technologist

I'm a first year computer science student. The programming paper I'm doing at Massey University is (unfortunately) in C#. And that s the language I'll use in the following examples.

From what I've understood about basic data types; an integer is a whole number, with no fraction or decimal value, and doubles and floats are numbers with a decimal value. This works well for most common calculations, but sometimes it is more accurate or convenient to store a value as a fraction; a quotient of two integers. There seems to be no data type like this in C#. Am I missing something? Looking in the wrong place perhaps? I started writing a C# struct for it. This needs a lot of revision and testing. I remember feeling very tired when I last stopped working on it and not even bothering to write todos, even though I had issues and use cases in mind. My testing has been very limited. I have no use for this for now so will probably not work on it for a long time, if ever again. Please let me know if it was useful for you:

/// <summary>
/// A quotient of two integers.  Commonly referred to as a fraction or rational number.
/// Strings formats contain one '/' character between two integers, e.g "2/3". 
/// Throws InvalidFractionException if the constructor is called with a badly formatted string.
/// Throws ZeroDenominatorException if denominator is set to zero.
/// </summary>
public struct Quotient
{
   int numerator;
   int denominator;

   /// <summary>
    /// Set a quotient by passing integer values for numerator and denominator.
    /// </summary>
    /// <param name="Numerator">Numerator</param>
    /// <param name="Denominator">Denominator</param>
    public Quotient(int Numerator, int Denominator)
   {
       numerator = Numerator;
       denominator = Denominator;
       checkDenominator();
   }

   /// <summary>
    /// Set a quotient by passing a string containing the '/' character. e.g. "3/4".
    /// Also accepts integers in string format without the '/' character, by setting the denominator to 1. e.g. "5" sets numerator = 5 and denominator = 1.
    /// </summary>
    /// <param name="Fraction">A rational number as a fraction in string format</param>
    public Quotient(string Fraction)
   {
       // Split the parameter into smaller parts
        char[] separator = { '/' };
       string[] parts = Fraction.Split(separator);

       // We can only handle this if there are either one or two parts
        if (parts.Length == 2 || parts.Length == 1)
           // Fall through to default exception if part is not integer
            numerator = Convert.ToInt32(parts[0].Trim());
       else
           throw new InvalidFractionException(Fraction);

       // If a denominator was specified, set it.  Else set denominator to 1.
        if (parts.Length == 2)
           denominator = Convert.ToInt32(parts[1].Trim());
       else
           denominator = 1;

       checkDenominator();
   }

   public override string ToString()
   {
       return numerator + "/" + denominator;
   }

   /// <summary>
    /// Convert the Quotient to a float
    /// </summary>
    /// <returns>The numeric value as a float</returns>
    public float ToFloat()
   {
       // Convert each to a float before performing division.
        return (float)numerator / (float)denominator;
   }

   /// <summary>
    /// Round the Quotient to the nearest integer
    /// </summary>
    /// <returns>Rounded value as Integer</returns>
    public int ToInt32()
   {
       // Add 0.5 for rounding
        return (int)(this.ToFloat() + 0.5);
   }

   /// <summary>
    /// Convert the Quotient to a double
    /// </summary>
    /// <returns>The numeric value as a double</returns>
    public double ToDouble()
   {
       // Convert each to a doubler before performing division.
        return (double)numerator / (double)denominator;
   }

   /// <summary>
    /// The numerator of the Quotient
    /// </summary>
    public int Numerator
   {
       get
       {
           return numerator;
       }
       set
       {
           numerator = value;
       }
   }

   /// <summary>
    /// The Denominator of the Quotient
    /// </summary>
    public int Denominator
   {
       get
       {
           return denominator;
       }
       set
       {
           denominator = value;
           checkDenominator();
       }
   }

   /// <summary>
    /// Checks that the denominator is a valid value (not zero).  Throws ZeroDenominatorException if denominator is zero.
    /// </summary>
    /// <returns></returns>
    private bool checkDenominator()
   {
       if (denominator == 0)
           throw new ZeroDenominatorException(numerator);
       return true;
   }
}

/// <summary>
/// The value passed into Quotient.Quotient(string Fraction) is invalid.
/// </summary>
public class InvalidFractionException : Exception
{
   string fraction;

   /// <summary>
    /// Constructor for InvalidFractionException
    /// </summary>
    /// <param name="Fraction">The string that should represent a fraction.</param>
    public InvalidFractionException(string Fraction)
   {
       fraction = Fraction;
   }

   /// <summary>
    /// The string that should represent a fraction but does not.
    /// </summary>
    public string Fraction
   {
       get
       {
           return fraction;
       }
   }
}

/// <summary>
/// The value of the denominator of a Quotient must not be zero.
/// </summary>
public class ZeroDenominatorException : Exception {
   int numerator;

   /// <summary>
    /// constructor for ZeroDenominatorException
    /// </summary>
    /// <param name="Numerator">The numerator of the quotient</param>
    public ZeroDenominatorException(int Numerator) {
       numerator = Numerator;
   }

   /// <summary>
    /// The numerator of the quotient
    /// </summary>
    public int Numerator {
       get
       {
           return numerator;
       }
   }
}