In C + +, an abstract class is a class having at least one abstract method given by the appropriate syntax in that language ( a pure virtual function in C + + parlance ).
32.
Over these two, respectively, collections of " mathematical classes " and of " abstract classes " have been built, the latter encompassing the most commonly used abstract data types in computer science:
33.
The "'Archetype pattern "'separates the logic from implementation; the separation is accomplished by there being two abstract classes, a decorator ( for logic ) and a delegate ( for implementation ).
34.
The subjective theory of value was able to solve this paradox by realizing that value is not determined by individuals choosing between entire abstract classes of goods, such as all the water in the world versus all the diamonds in the world.
35.
Traits are similar to mixin classes in that they have nearly all the power of a regular abstract class, lacking only class parameters ( Scala's equivalent to Java's constructor parameters ), since traits are always mixed in with a class.
36.
Concept of Object Oriented Programming Data hiding, Data encapsulation, Class and Object, Abstract class and Concrete class, Polymorphism ( Implementation of polymorphism using Function overloading as an example in C + + ); Inheritance, Advantages of Object Oriented Programming over earlier programming methodologies,
37.
On January 1, 2010, Free Pascal 2.4 . 0 was released, followed on November 13, 2010, by bug fix release 2.4 . 2, with support for for . . in loops, and sealed and abstract classes, and other changes.