Approach to C# Programming

What is C#?

C# is a server side programming language, which is developed by Microsoft.

C# gives the functionality of the application.

C# is a object oriented programming language which consists of classes and objects.

Environment Setup

Process to setup C# from Notepad. We can write C# programs using Notepad also. To be able to compile and run c# from notepad we have to set the following path from command line.

Enter the total path and enter csc to check c# compiler is added.

Writing a Basic C# Program

 Step1: Program in Notepad and save in specified folder to identify.

 Step2: Compile  the program

Step3: Run the program 

Variable Declaration

• Variable is a memory pointer declared to store some value.
• It can be any name given but should not exceed 32 charecters.
• Should start with character only or underscore(_).

   Syntax: Datatype Variable_Name;

Defining a Class and Object

   Class is a blue print and logical representation of object.

  Object is a physical representation of class. Takes all the members from class.

   Syntax to define class:   Class Class_Name
                                         {
                                               // Class members
                                         }


   Syntax to define object: Class_Name object_name= new Class_Name();

   Program to specify usage of Class and Object.   

Conditional Statements

1.   if() statement:

2.   if...else() statement:

2.  Switch() statement:

Looping Statements

Looping statements are used to iterate a block of statements until a specified condition becomes true.

Looping statements are : for(), while(), dowhile(), goto(). 

Iteration is an execution of block of statements for one time. When a sequence of instructions is executed in a repeated manner until condition becomes false, it is called a loop.

1.   for() loop:

 For statement is used whenever the number of iterations are fixed or known.

 Syntax: for(expression1;expression1;expression1)

             {

                       //block of statements

             }

2.   While() loop:

Syntax: While(Condition)

             {

                       //block of statements

             }

String Manipulation

   1. Reading and displaying a string

    

2. String Concatenation

  

   

3. Searching a String ( indexOf() function):

  

4. Substrings ( substr() ):

    Substring is a string function used to search and return a string based on index.

   Syntax: string.substr( Starting_position, No_of_charecters )

   

5. Comparing string ( Compare() ): 

   Compare() function is a static function compares two string and returns zero if equal.

  Syntax: String.Compare(“string1”,”string2”).

  Compares string2 with string1.

File Handling

  Example to Parse Menu

  Program:

  File Input Given

  Output

  Output Generated