Abstract Class in c#.net

Abstract Class:

Now we will discuss about abstract class in c#.net.

·         Abstract class is class we cannot create object. We only use inherit

·         We are only use base class. If u r use abstract method u must implement derived class

Abstract Class Declaration

abstract class devenvexe

{

}

A abstract class can contain  abstract method or non-abstract method .abstract method not have implementation in abstract class .but same its have derived class

Abstract Method/Non Abstract Method:

abstract class devenvexe

{ 

public abstract void abstractMethod();

public void NonAbstractMethod()

    {

        Console.WriteLine("NonAbstract Method");

    }

}

Rules:

·         Abstract class not have sealed class

·         Abstract class only contain abstract method

·         Abstract class cannot be private

·         Abstract method cant have virtual keyword.because its  explicit virtuval method

·         Abstract class cannot be static

Performance

In our testing, abstract classes with virtual methods have better performance than interface implementation .

Reserve word in C#.net

Keywords in C#.net

C#.net have  77 Reserve word. You are  not declare variable/method in reserve words .if you want to declare reserved word you can use " @ "  symbol.

Example:

private void btn_Click(object sender, EventArgs e)         {             string string="Welocme to DevEnvExe"         } Suppose if you want use above coding private void btn_Click(object sender, EventArgs e)         {             string @string="Welocme to DevEnvExe"         } Below list are C#.net reserve words unchecked unsafe ushort boolirtual class abstract as base byte char decimal int sbyte uint ulong break case catch finally checked const continue default delegate do double else enum event explicit extern false fixed float for foreach goto if implicit in interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sealed short sizeof stackalloc static string struct switch while this throw true try typeof using void volatile