Abstract Classes and Final Classes in Delphi
Abstract Classes in Delphi If a Class have at least one Abstract member then we call it Abstract Class. An Abstract member is a Class member that have only declaration on that class and the implementation of that member is expected to be done in its descendant classes. An Abstract Class can have normal methods also. In Delphi it allows to create Object of an Abstract Class but we should not create because when we try to access any Abstract member then we will get run time exceptions. And if a class is having only Abstract members then it is called as pure Abstract class. Why we use Abstract Class? An Abstract Class is written when there are some common features are shared by all the objects. Suppose in your project if you have some common features then declare that type of properties and methods as Abstract and you can extend wherever you want in your Module For example... If you want to make a new car(WagonX) in which all the another car's properties are included like color,size,