C#.NET

1. .NET Framework:
 .NET IS A FRAMEWORK TOOL AND IT IS AN INTEGRAL
WINDOWS COMPONENT THAT SUPPORTS BUILDING
AND RUNNING THE NEXT GENERATION OF
APPLICATIONS AND XML WEB SERVICES.
 .NET SUPPORTS 61 PROGRAMMING LANGUAGES OUT
OF WHICH 9 ARE DESIGNED BY MICROSOFT.

2. VERSIONS:

3. .NET COMPILATION
In .Net code is compiled twice.
In first compilation source code is compiled by
respective language compiler and an intermediate
code is generated known as MSIL (Microsoft
Intermediate Language).
In second compilation MSIL is converted into Native
code using CLR.

4. Framework Class Library (FCL)
Framework class library is a huge library of reusable
types for use by managed code.
It is the library of classes, interfaces and value types
that provides access to system functions.
It is designed to be the foundation on which .Net
framework applications, components and controls
are built.

5. The hierarchy of class library-----

6. Namespace
• Namespaces are the reusable concept in c#.net.
• Every namespace is a DLL file.
• Microsoft implemented object oriented programming
concept in the namespaces.
• It is a container that provides context for the identifiers.
• A namespace provides classes, structures, enumerations,
delegates, interfaces and other namespaces.

7. Namespace contd. :
• In .net framework “system” is the base namespace.
• Ex:
• using System;
• using System.Data;
• using System.Collections.Generic;
• using System.Windows.Forms;
• using System.Text;
• using System.Linq;
• using System.Threading;
• using System.Drawing;

8. Namespace contd. :
• To declare scope for types in a namespace………
• Namespace NamespaceName
• {
• Class ClassName { }
• Interface InterfaceName { }
• Struct StructureName { }
• Enum EnumerationName {a,b}
• Delegate void DelegateName (int i);
• Namespace NamespaceName.Nested
• {
• Class ClassName { }
• }
• }

9. Structure of C#.Net program
• List of Class Library Namespaces
• Namespace Namespace Name
• {
• Class Class Name
• {
• Static void main (string [ ] args)
• {
• Statements;
• }
• }
• }

10. Escape Sequence:
• n new line
• r carriage return
• t horizontal tab
• v vertical tab
• b backspace
• f form feed
• ’ single quote
• ” double quote
• backslash
• 0 null
• a alert

11. Identifiers:
• Identifiers are the sequence of characters used to identify
variable, constants, properties, methods, object, types etc.
• C# identifiers are case-sensitive i.e. variable names sum,
Sum, SUM are different from each other.
• An identifier must begin with either a letter or an
underscore.
• It must not be a reserved keyword.
• It must be a complete word without any blank space.

12. Keywords:
• Keywords are predefined, reserved identifiers that have
special meanings to the compiler.
• They are similar to the identifiers but you can’t use them as
variable names, methods and properties.
• If you want to use the keywords as identifiers, prefix the
keyword with ‘@’ character.

13. Constant:
• A constant is a type but its value is fixed throughout the program
execution. Once the program gets compiled its value can’t be
changed.
• A variable is declared as constant using “const” keyword.
• Constants are useful when you know the value of a variable at
compile time.

14. Console:
• Console is a class used to work with input and output streams.
• This class is present in System namespace.
• This class has following methods/functions……
• Write(“message”)
• WriteLine(“message”)
• Read()
• ReadLine()
• Clear()

15. OPERATORS

16. Primary:
• x.y : dot – used to access member variables and methods of a class
• f(x) : parenthesis – used to convert the types
• a[x] : square brackets – used with arrays, pointers and attributes
• x++ : post increment
• x-- : post decrement
• new : used to create objects and call the constructors

17. Unary:
• + : unary plus
• - : unary minus
• ! : logical complement
• ~ : bitwise complement
• ++x : pre-increment
• --x : pre-decrement

18. Foreach:
• It continues to execute the loop body for each element in an array or
object collection.
• Here the data type of loop variable must be same as data type of
array/collection.
• Syntax….
• Foreach (datatype variable in array/list collection name)
• {
• Statements;
• }

19. ARRAY TYPES:
• Normal array : An array which occupies a memory size of less than 64kb is
known as normal array.
• Huge array : An array which occupies a memory size more than 64kb is known
as huge array.
• Static array : An array whose physical size is fixed and can’t be changed at
runtime is known as static array.
• Dynamic array : An array whose physical size is not fixed throughout the
program execution and can be changed at runtime is known as dynamic array.
• Array size can be changed during program execution using “Resize( )” of array
class.
• Jagged array : An array which contains another array within it is known a jagged
array. It is also called array of arrays.

20. SYNTAX OF ARRAYS:
• datatype[ ] array name = new datatype [size];
• datatype[ ] array name = new datatype [size]
{initializing elements};
• datatype[ ] array name = new datatype [ ]
{initializing elements};

21. Array Object:
• When we create any array with any name then the array is treated as an
object.
• “copy to()” method of array object is used to copy elements of one array
to another array.
• Syntax:- array object.copyto(destination array,index);
• “length” property of array object returns the size of an array.
• Syntax:- array object.Length
• “rank” property returns the number of dimension present within the
array.
• Syntax:- array object.Rank

22. Array class:
• reverse(array name, *int index, *int length);
• sort(array name, *int index, *int length);
• clear(array name, *int index, *int length);
• copy(source array, *int source index, destination array, *int
destination index, int length);
• * are optional