Define rules of Constructors

• Its name must be same as "classname".
•  It must be defined as "public method".
•  It can be defined with/without arguments.
•  It can't return any value. So, no return type specification is required.
• "Constructor overloading" is possible. Writing multiple constructors in the same class is called as "Constructor overloading".

Define “this” Keyword

This is similar to ―this pointer in C++.
 It represents current working object.
 It is used to access the members of current working object.

• this.field
• this.property
• this.method()

Current object: The object, with which object, the method is called.
“this” keyword can‘t be used in the static methods, because static methods doesn‘t have current object.

Define Variable Scopes

•  A variable scope simply is something, which decides the lifetime of the variable.
•  The variable scope depends on the place, where the variable is declared in the program.

 For example,
     a variable is declared in if block, is available only within the if block itself.  To have a better idea on this, we discuss about all available scopes in C#.

Define Variables

 Variable declaration:
Syn: datatype variable;

Ex: int x;

Variable declaration along with initialization:
Syn: datatype variable=value;

Ex: int x=10;

Multiple Variable declaration:
Syn: datatype variable1, variable2, variable3,…;

Ex: int x,y,z;

Note:
     When we declare any variable, it should be assigned to a value before its usage.Otherwise, it causes a compile time error.

Define string[] args

   To receive the command like arguments. A command line argument is nothing but an argument, which can be passed from the command window, before the application execution is started.

Define void

It can‘t return any value unlike other methods. So that, it should be defined with void keyword.

Define Memory Manager

 The Memory Manager component of CLR, allocates necessary memory for the variables and objects that are to be used by the application.

Define Exception Manager

•  An exception means Run time error.
•  This component redirect the processor to execute the catch block or finally block,whenever an exception is occurred at run time.
•  We can learn how to write these catch and finally blocks in C#.NET and VB.NET languages later.

Define .NET Framework Types

The .NET Framework is available in 3 different types:
 .NET Framework: 
         This is the general version, required to run .NET applications on Windows operating system.
 .NET Mono Framework: 
         This is required to run .NET applications on other operating systems like UNIX, LINUX and Solaris etc.
 .NET Compact Framework:
            This is required to run .NET applications on other devices like PDA (Personal Digital Assistants), Mobile phones and Smart phones.

Define Web Services

Web Services

•  Web Services are simple and easy to understand.
•  These can be developed using again ASP.NET.
•  The web services are used to implement SOA(Service Oriented Architecture) in web applications.
•  The main purpose of SOA is to implement some interaction between two applications.
•  Examples:
•   Online shopping requires credit card authentication, from back web site.