Abstract method

Abstract method

1. ABSTRACT CLASS

2. ABSTRACT CLASS Definition: T he class is created for the purpose of providing common fields and members to all subclasses then this type of class is called an abstract class . While we are declaring a class if we used abstract keyword that is abstract class. Abstract class is a collection of abstract members and non abstract members.

3. Syntax for Abstract class: a bstract class <class name> { //abstract Members; or //Non abstract members; } ABSTRACT CLASS We can use abstract key word for Properties , events & methods ,So an abstract class can contain abstract properties ,abstract events and abstract methods

4. ABSTRACT CLASS Abstract Method: Abstract members can contain only declaration part in abstract class that means it will contain only skeleton of the member. The definition of abstract member (or) implementation of abstract member should be in derived class. We should implement abstract members in derived class using override keyword. Syntax For Abstract method: abstract <return type> <method name>(); Example: abstract void display();

5. ABSTRACT CLASS Abstract class can not be instantiated, that means we can not create object for abstract class. We have to access members using derived class object only. Syntax for Abstract Property: a bstract <data type> <property name> { get; set; }

6. ABSTRACT CLASS We can not declare abstract class as a sealed class because sealed class will not inherited to derived class. If we declare abstract class as a sealed class we can not implement abstract members in derived class. Example: a bstract sealed class Demo { } o/p: Error

7. ABSTRACT CLASS We can not use private access modifier for abstract class as well as abstract members. Because we can not access that abstract class members in the derived class. Example: p rivate abstract void display(); { } o/p: Error

8. ABSTRACT CLASS By default abstract members all are virtual . We can not use virtual key word for abstract members. Access modifier of a abstract member should be same in the abstract class and derived class. Ex: public abstract void Demo { public void m1(); } public class Demo1:Demo { public override void m1() {; } }

9. THANK YOU!!