Code Samples

Enumerations:

1. Coin + CoinFace – The CoinFace enumeration helps to describe the two sides of a Coin, which can then be used in a tossing game.

2. Account + AccountType – The Account's account type is no longer being represented as a string, but is its own enumeration: AccountType.

3. LetterGrade + QuebecLetterGrade – The QuebecLetterGrade uses the simple LetterGrade enumeration and assigns specific ranges of percentage marks for the possible LetterGrade values.

4. CampsiteFacility - Introduces the idea of the [Flags] attribute on the enumeration.

Composition:

1. Address + Student + GenderType – This revised version of the Student class now has an Address field. The address field is new; although similar to the CanadianAddress class, the Address class is simpler and more "generic" (having "State" instead of "Province" and "ZipCode" instead of "PostalCode").
2. ImproperFraction + MixedNumber + ProperFraction – In this sample, the idea of a Fraction class is made more specific by replacing it with three more specific types of numbers: MixedNumber, ProperFraction, and ImproperFraction. A MixedNumber is made up of a whole number and a ProperFraction. A MixedNumber can also be expressed as or derived from an ImproperFraction. The reciprocal of a ProperFraction is an ImproperFraction and the reciprocal of an ImproperFraction is a ProperFraction.