overloading-------having same method name with different 
signatures.
 overriding--------methods name and signatures must be same.

OverLoading :  All the method will share the same name but 
it differes based on the parameter, type of parameter and 
number of parameter

Overriding : The method in the derived class the has the 
same name in the base class and it changes the behaviour or 
functionality of the method in the base class.

Overloading: Methods have different signature but same
behavior or functionality.

Overriding: Methods have same signature but different bevior
or functionality.

overloading has same method but different types of 
parameters, number of parameters.

overloading does not take return type to differentiate 
overloaded method.

ex:
int add(int a, int b)
int add(float a , float b)
are overloaded methods

overriding comes with inheritance concept.
here parent and child both contains the same method. and 
when execution takes place; child's method is called.

OVERLOADING is the process of declaring the methods having 
the same name but diff signatures. Signature means diff 
types & number of arguments.

OVERRIDING is the process of overwriting the methods of 
base class in Derived Class.

overriding: it just in inheritance  and the overriding
method must hold the same name and the same signatures .
the change maybe just in behavior .

overloading : maybe in inheritance or in other way but must
to do overloading must the method hold the same name and
must change signatures.
remark:we can not only change th return type.

1-OverLoading is Resolved at COMPILE TIME.But Overridding is
resolved at RunTime.

2-OverLoaded Methods Can Change Access specifiers.in
overridding the access level of overridden method(in derived
class) must not be more restrictive than that of overridden
method(of base class)

3-Overloaded methods can declare new exceptions.But
overridden method must not throw new exceptions than those
declared by overridden method.

When global and local varible  in the same name.
the local varibale in a mehod or function which use to 
override the global is called the shadowing.
ie the Global varible is being shadowed by the 
local varible

If there are overloaded methods in the base class, & u 
marks one of the methods as shadows using the keyword 
shadow in the derived class, then we cannot access the 
overloaded methods.

Ex-
public class base
  public sub test()
console.writeline("sonia")
 end sub

public sub test(i as integer)
 console.writeline(i)
end sub

end class

public sub derived
inherirts base
 shadows sub test(x as integer)
console.writeline("Shadow method")
end sub
end class


sub main()
dim obj as new derived
obj.test()-->Invalid
obj.test(10)-->Valid
end sub

its a class which can not be instantiated...the class must 
be inherited and the methods can be overridden.

It is a class which contains at least one abstract method 
(A method without any implementation). Other methods can 
have implementations. This class can not be instantiated. 
It can always become a base class for other classes.

We cannot create an object of object class. abstract Class 
must be inherited.

Protected variable will be accessed in inherited class, but 
instance variable of class cant access protected variable.

While friend variable will be accessed in inherited class 
as well as instance variable of class across the project.

Where we need both functionality we are using protected 
friend scope.

friend------access is limited to the current assembly
(application)
protected friend----access is limited to the current 
assembly and types derived from the containing class..

Protected --> Accessible ONLY by 1.Derived classes 2.Within 
the same class

Friend --> Accessible ONLY by 1.Derived classes 2.Classes 
in the same assembly 3.Within the same class

Protected Friend --> Accessible ONLY by 1.Derived classes 
2.Classes in the same assembly 3.Within the same class


This is a very strange prob for which I've been looking for 
an answer for a long time. As you can see above Friend and 
Protected Friend are exactly same simply because 'Friend' 
encompasses the accessibilities of both Protected and 
Protected Friend. The question here is  why did Microsoft 
publish a 'Protected Friend' keyword when it is EXACTLY 
same as Friend.

Friends can be accessed by all classes within assembely but 
not from outside the assembely.

Protected variables can be used within the class as well as 
the classes that inherites this class.

The Protected Friend can be accessed by Members of the 
Assembely (Friend) or the inheriting Assembely class 
(Protected).

So Friend is not same as Protected Friend

I guess the difference is this:
Friend can be accessed by
1. Code within the class
2. Code in derived classes within the same assembly
3. Other code in the same assembly

Protected can be accessed by
1. Code within the class
2. Code in derived classes within the same assemblies
3. Code in derived classes in other assemblies

Protected Friend can be accessed by
1. Code within the class
2. Code in derived classes within the same assembly
3. Other code in the same assembly
4. Code in derived classes in other assemblies

system.reflection

System.Data.Common

system.process.diagnostics

It's Simply Syste.diagnostics

Not syste,process.diagnostics

Comman for all provider as Oledb, Sql
Imports System.Data.Object
-> object is provider(Database)

maintain the all structure of sql database
Imports System.Data.SqlClient

CLR is the common language runtime. which is the feature 
makes the .net applications to run plantform independent 
langauge interoperability. 

CTS Common type system is the  part of the CLR which enable 
the Common Datatype system to All the .net languages.
it also defines conventions to convert objects from one 
langauge to another

CLR (comman anguage runtime) is the heart of the .net 
framework. every runtime has responsibility to take care of 
code at the time of execution.for ex vb  has MSCRT60 AND 
java has JVM and In .net CLR.
WHILE CTS ( comman type system) is subset of CLR .it 
provide smooth comunication between two language.for exp in 
vb .net has integer and c# has int ,CTS change both into 
system.int32. 
By Anamika Srivstava

CLR means Common Language Runtime.It is  Major component of 
the .NET frameworkIt provides no of benefits to the 
developers such as Exception handling,Security,Debugging 
and Versioning...

Common Language Runtime is Runtime engine which converts 
Microsoft Intermediate Language in machine understandable 
code, it is similar to JVM in Java

CLR is an execution engine for .net.It is used to convert 
the highlevel language code into MSIL(Microsoft 
Intermediate Language).So this MSIL again converted into 
m/c language by JIT compiler(Just In Time).

The CLR is the main coponent for .Net framework.So the .Net 
framework supports 44 languages.

kamal...

Full of CLR is Common Language Runtimeand its forms the 
heart of thye .NET Framework. All language have rumtime and 
its the responsibility of the runtime to take care of the 
code execution of the program.

CLR actually take care ofentire execution, memory managment 
of .net applicatin.COde that u developed with alanguage 
compiler that targets runtimeis called as managed code; it 
benifits from from feature such as cross language 
integartion, cross-language exception handlaing, enhance 
securityversion & deployment support 
This runtime is allocated by visual studio.NET IDE is 
called as runtime host.
it's benifitsw are 

1.it improve Performance
2.ability to easily use compopnant developed in other 
languages
3.Cross language integration,espacially cross-language 
inheritance
4.Garbage collection
5.slf describing obj which makes using IDL unnecessary
6.The ability compile once & run on any CPU & operating 
system that support the runtime

its a comman Language Runtime

CLR is Comman Language Runtime engine is used to excute the
compiled code.

CLR is the execution engine of .net. whenever an execution 
command is given the cls progra activates a 'jit' compiler 
which inturn interprets the program according to the 
operating system standards and then execution takes place

System

Imports system

system.object

System is root namespace for all types

in vb.net
imports System.data.sqlclient
in c#
using System.data.sqlcient

It is a reference type

The interface is the one in which all the methods are empty 
one but in the abstract class it is not necessary that all 
the method has to be abstract .it can be only one method 
that is abstract

In both Interface and Abstract classes we cannot create a 
object but abstract classes can be inherited and we can 
create a object for that derived class.

Abstract classes may contain concrete methods as well as an 
Implementation of methods where as Interface doesn't 
contain any implementation it just contains concrete 
methods and to use those methods in interface we need to 
inherit that interface and have to make sure that all 
methods in the interface are implemented or else even the 
derived class becomes an Interface.

c 
c++ 
vb 
c#   
Cobol
Perl
visual c#

APL,C++,C#,Cobol,,Component
Pascal,Curriculum,Eiffel,Forth,Fortran,Haskell,Java
Language,Microsoft
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Talk,Standard ML,Microsoft Visual Basic