What are members of abstract class? Hints: List member types in an abstract class Use case Syntax and code example Which can / cannot be member of abstract class? Why?

Members of an abstract class can include the following types:

1. Fields: These are variables that store data within the abstract class. They can be of any valid data type and are declared using the appropriate syntax for the programming language being used. For example, in Java, a field can be declared as follows: private int myField;

2. Methods: These are functions that define the behavior of the abstract class. They can have parameters, return types, and a method body that contains the implementation details. The syntax for declaring a method in an abstract class depends on the programming language. For instance, in C#, a method can be declared as follows: public abstract void MyMethod();

3. Properties: These are special methods that provide access to the fields of the abstract class. They allow for controlled reading and writing of the data stored in the fields. The syntax for declaring properties varies depending on the programming language. For example, in Python, a property can be defined using the @property decorator.

4. Constructors: These are special methods that are used to initialize objects of the abstract class. They are typically used to set initial values for the fields of the class. The syntax for declaring constructors also depends on the programming language. In C++, a constructor can be declared as follows: MyClass() { // constructor code }

5. Nested classes: These are classes that are defined within the abstract class. They can have their own fields, methods, properties, and constructors. The syntax for declaring nested classes depends on the programming language. For example, in C#, a nested class can be declared as follows: public class MyNestedClass { // nested class code }

Certain members, such as static members and final members, can be part of an abstract class. However, it is important to note that abstract classes cannot be instantiated directly, meaning you cannot create objects of the abstract class itself. Instead, you need to create a subclass that extends the abstract class and then instantiate objects of the subclass.

The reason for this limitation is that abstract classes are meant to be partially implemented and serve as a blueprint for other classes to inherit from. They provide a common interface and define common behavior that subclasses must implement. Therefore, it is not possible to create objects of an abstract class directly because it may have incomplete or undefined behavior.