1. Introduction to C#

 1.     The C# Language

–      The language of choice in the .Net environment

–      Combines

•       the power and efficiency of C++

•       simple and clean OO design of Java

•       language simplification of VB.

2.     C# Basic Syntax Rules

•       C# is case-sensitive.(‘c’ !=‘C’)

•       Each statement ends with a semicolon.

•       To group statement, use curly braces.

•       To tell C# that the statement is a comment, use either of these symbols.

// single line comment

  /* multiline comments*/

•       More rules as we go along.J

3.     C# Console Program Structure

using <namespace>;

namespace <name>

{

                          class <name>

                        {          

                                    static void Main(String [] args)

                                    {

                                    //statement(s)

                                    }

                        }

} 

Example:

using System; //Console.WriteLine ( ) is found in this namespace.

namespace HelloWorld //classify each project in a solution.

{

                    class Program //classify each object in a namespace

                  {          

                              static void Main(String [ ] args)//entry point of the program

                              {                      

                              Console.WriteLine(“Hello World”); //display Hello World

                              }

                  }

} 

4.     C# File Structure

5.     C# Commonly Used Data Types

–      Numeric Data Types

•       short (-32,768 to 32,767)

•       int (-2,147,483,647 to 2,147,483,647)

•       long (-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)

•       float (+/-1.5 * 10-45 to approx.+/-3.4 * 1038)

•       decimal (28 digits. Requires the suffix "m" or "M.“)

•       double (+/-5.0 * 10-324 to approx. +/-1.7 * 10308)

–      String/Character Data Types

•       char (holds a single character)

•       string (hold string of characters)

–      Boolean/Logical Data Type

•       bool (true/false)

6.    Variable Declaration

examples

–      int  num;

–      char middleInitial;

–      string firstName;

–      bool found;

–      double salary;

–       

7.    Accept Input and Display output

using System;

namespace Profile

{

    class Program

    {

        static void Main(String[] args)

        {

            string name;

            int age;

            float weight;

            Console.Write("Input name:");

            name = Console.ReadLine();//(By default,C# read input as string) read input and assign it to name

            Console.Write("Input Age:");

            age = int.Parse(Console.ReadLine()); //Read input, convert it to int, assign it to age.      

            Console.Write("Input  Weight in kgs.:");

            weight = float.Parse(Console.ReadLine());//Read input, convert it to float, assign it to weight.      

            //{n}-refers to the placement of the variable separated by comma.

            //{0}-name {1}-age {2:N2}-weight in two decimal places.

            Console.WriteLine("You are {0},your age is {1} and you are {2:N2} kgs.", name, age, weight);

        }

    }

}