The document compares C# 3.5 and C# 4.0, highlighting key differences in support for dynamic programming, keywords like dynamic, creation of dynamic variables, optional parameters, named parameters, indexed COM properties, and generics with co/contra-variance. It also compares C# and VB.NET in areas like variable declaration, object creation, return types, overloading, default properties, inheritance, operators, and comparisons. Finally, it contrasts C# and C++ in their levels of abstraction, memory management, switch statements, flow control, class members, exceptions, and function pointers.

1. 1.Difference between C# 3.5 and C# 4.0
S.No C# 3.5 C# 4.0
1 C# 3.5 does not support dynamic C# 4.0 supports dynamic programming
programming. through dynamic objects.
2 The dynamic keyword is not In C# 4.0, dynamic keyword is
recognized in C# 3.5. associated with objects to represent
them as dynamic objects.
3 Dynamic variables cannot be C# 4.0 allows creation of dynamic
created in C# 3.5. variables.
4 In C# 3.5, method parameters In C# 4.0, the method parameters can
cannot be specified with default be specified with default values using
values. C# 3.5 does not support optional parameters.
optional parameters.
5 In C# 3.5, method parameters C# 4.0 provides named parameters to
have to be specified in the same represent the values of method
order as in method declaration in parameters without following the order
the method call. C# 3.5 does not of declaration.
provide named parameters.
6 In C# 3.5, usage of ref keyword is In C# 4.0, usage of ref keyword is
mandatory while executing optional while executing methods
methods which are supplied by which are supplied by the COM
the COM interfaces. interfaces.
7 The COM object’s indexed The COM object’s indexed properties
properties are not recognized in are recognized in C# 4.0.
C# 3.5.
8 Co-variance and contra-variance C# 4.0 enhances Generics by
are not supported in Generics of introducing co-variance and contra-
C# 3.5. variance.
2.Difference between C# and VB.NET
S.No C# VB.NET
1 In C#, variables are declared using In VB.NET, the variables are declared
declarators. using keywords such as private,
protected, friend, public, static, shared
and Dim.
2 In C#, an object can only be In VB.NET, an object can be created
created using new. using new and CreateObject().
3 In C#, void is specified as the In VB.NET, Sub is used in method
return type when a method does declaration to indicate that the method

2. not return a value. does not return any value.
4 In C#, no keyword is required to In VB.NET, Overloads keyword is
indicate an overloaded method. used to indicate an overloaded method.
5 The current object is referred The current object is referred as me in
using this pointer in C#. VB.NET.
6 Non virtual call cannot be made in To make a non-virtual call to the
C#. current object’s virtual method,
MyClass is used in VB.NET.
7 Compound data type is declared Compound data type is declared in
in C# using class, struct and VB.NET using Structure.
interface.
8 In C#, constructors are used to In VB.NET, Sub New() is used to
initialize an object. initialize the newly created object.
9 Object cleanup can be explicitly Object cleanup can be done by using
done by destructor in C#. Finalize method in VB.NET.
10 In C#, an object is subject to In VB.NET, an object cannot be
asynchronous modification using modified in an asynchronous way.
volatile keyword.
11 In C#, all the variables have to be In VB.NET, variables can be forced for
declared before being used. explicit declaration using Option
Explicit.
12 In C#, default property is defined In VB.NET, default property is defined
by using indexers. using Default.
13 In C#, base class can be referred In VB.NET, base class can be referred
using the keyword ‘base’. using the keyword ‘MyBase’.
14 Abstract class of C# can only be MustInherit keyword of VB.NET is
inherited and not instantiated. used to denote that a class can only be
inherited and not instantiated.
15 Sealed keyword of C# is used to NotInheritable keyword of VB.NET
denote that a class cannot be denotes that the class cannot involve in
inherited. inheritance.
16 Division can be performed in C# Division can be performed in VB.NET
using / operator. using operator.
17 Remainder of division can be Remainder of division can be retrieved
retrieved using mod operator of using %.
C#.
18 C# does not have exponentiation In VB.NET, exponentiation can be
operator. performed using ^ operator.

3. 19 C# has Bitwise operators namely Bitwise operators in VB.NET are And,
&,| and ^. Or, Xor.
20 Object reference variables can be Object reference variables can be
compared using == operator in compared using Is operator in
C#. VB.NET.
21 The short ciruit operators in C# The short circuit operators in VB.NET
are && (Boolean AND) and || are AndAlso (Boolean AND) and
(Boolean OR). OrElse (Boolean OR).
3.Difference between C# and C++
S.No C# C++
1 C# is a high level language that is C++ is a low level and indeed platform
component oriented. neutral programming language.
2 When compiled, C# code is When compiled, C++ code is
converted into Intermediate converted into assembly language
language code. This intermediate code.
language code is converted into
executable code through the
process called Just-In-Time
compilation.
3 In C#, memory management is In C++, the memory that is allocated in
automatically handled by garbage the heap dynamically has to be
collector. explicitly deleted.
4 In C# Switch Statement, the test In C++ Switch Statement, the test
variable can be a string. variable cannot be a string.
5 In C# switch statement, when In C++ switch statement, when break
break statement is not given, the statement is not given, the fall through
fall through will not happen to the will happen to the next case statement
next case statement if the current even if the current case statement has
case statement has any code. any code.
6 In addition to for, while and C++ does not contain for each
do..while, C# has another flow statement.
control statement called for each.
7 C# struts can contain only value C++ struts behave like classes except
types. The struts is sealed and it that the default access is public instead
cannot have a default no-argument of private.
constructor.
8 In C#, delegates, events and In C++, only variables, constructors,
properties can also be specified as functions, operator overloads and
class members. destructors can be class members.

4. Delegates, events and properties
cannot be specified as class members.
9 In C#, the end of the class In C++, the end of the class definition
definition has a closing brace has a closing brace followed by a
alone. semicolon.
10 The access modifiers in C# are The access modifiers in C++ are
public, private, protected, internal public, private, protected. C++ does
and protected internal. not have internal and protected internal
access modifiers.
11 C# has finally block in exception C++ does not have finally block in
handling mechanism. The code exception handling mechanism.
statements in the finally block will
be executed once irrespective of
exception occurrence.
12 The exception in C# can only The exception in C++ can throw any
throw a class that is derived from class.
the System.Exception class.
13 C# does not have the concept of C++ has the concept of function
function pointers. C# has a similar pointers.
concept called Delegates.
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