1 session 01 module 1: introduction to c# module 2: variables and data types

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Session 01

Module 1: Introduction to C#

Module 2: Variables and Data Types

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Module1 - Objectives

Describe the .NET Framework List the other components of .NET Framework Explain CLR and MSIL Define Memory Management and Garbage

Collection Describe the Microsoft Visual Studio 2005 product Learn the key elements of Visual Studio 2005

IDE List the basic features of C#

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Architecture of .Net Framework(1)

The .Net Framework is a multi-lingual environment to build, deploy and run applications

It enables programmers to develop applications for various platform such as mobile devices, desktop computer, smartphones and so on.

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Architecture of .Net Framework(2)

The .Net Framework architecture comprises of following: Languages included in the .Net Framework .Net Framework class library (FCL) The Common Language Runtime(CLR)

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Architecture of .Net Framework(3) Other importance components in .Net Framework

Web Forms Web services Windows Forms ASP.NET ADO.NET XML Classes Base Framework Classes Common Language Specification Common Type System

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Microsoft Intermediate Language(MSIL)

When code written in .Net Framework language such as C#,VB…is complied, output code is in the form of Microsoft Intermediate Language(MSIL)

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Common Language Runtime(CLR)

When a code is executed for first time, the MSIL code is converted to a code native to operating system.

This is done ar runtime by the Just-in-Time(JIT) compiler present in CLR.

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Basic Features of C#

Object-oriented programming language Type safety checking Garbage collection Standarbisation by ECMA(European

Computer Manufacturers Association) Generic Types and Methods

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Visual Studio 2005(1)

Visual studio 2005 is complete set of development tools to build desktop applications, web application, XML web service and mobile applications.

Primary advantages are: Development of applications for .Net Framework

2.0 Development of applications for handheld devices

using .Net Compact Framework 2.0

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Visual Studio 2005(2)

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Key elements of VS 2005

Solution Explorer Code Editor Properties Window Dynamic help

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Write and run first console application

Step 1: Create new project

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Write and run first console application Step 2:Compile program

You can compile console application from command line or use IDE

If compile program from command line:

Edit PATH variable, add following line in PATHC:\WINDOWS\Microsoft.NET\Framework\v2.0.50727;

in command line window, change to directory of program and type: csc <fileName.cs>

If use IDE, press F6 to compile program

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Write and run first console application

Step 3: Run program If use command line window, type .exe file name If use IDE, press Ctrl + F5

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Module 1 – Summary (1)

.Net Framework is multi-language platform to build, deploy and run various types of applications

Two major components of .Net Framework is CLR and FCL

When code is written in .Net language such as C#,VB…compiled, output code is converted to code native to operating system by Just-In-Time language

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Module 1 – Summary (2)

C# is an object-oriented programming language derived from c and C++.

C# support features like type-safety checking, garbage collection, ECMA standardization, generics

Visual studio 2005 is complete set of tool to build high performance applications

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Module 2 - Objectives

Identify basic data types in C# Explain XML source code documentation List the keywords in C# Describe reference data types Constants and Literals Describe console output methods in C# Explain number and datetime format

specifiers

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Variables

A variable is an entity whose value can keep changing

Declaration syntax:<datatype> <variableName> [,variableName=<value>];

Assignment syntax: <variable> = <value>;

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Data Types (1)

In C#, data types are also divided into two categories: Value types:

Can be either the built-in data type or a user-defined data type.

Stack storage results in faster memory allocation to variables of value types

Reference types: Variables of reference type store the memory address

of other variables in a heap. Most of user-defined data types such as class are

reference types.

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Data Types (2)

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Predefined Data Types (1)

The predefined data types are referred to as basic data types in C#.

These data types have a predefined range and size.

The size of the data type helps the compiler to allocate memory space and ensure the value assigned is within the range of the data type.

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Predefined Data Types (2)

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Reference Data Type Classification

Reference types can be classified as

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Some Reference Data Types

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Variable Naming Rules

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Comments

Comments are given by programmer to provide information about a piece of code.

Comments make the program more readable. Comments help the programmer to explain the purpose

of using a particular variable, method, class, or code snippet.

Comments are ignored by the compiler during the execution of the program.

C# supports three types of comments: Single-line comments Multiple-line comments XML comments

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XML Documentation

In C#, we can create an XML document that will contain all the XML comments.

This document is useful when multiple programmers want to view information of the program.

To create an XML document, we must use the VS 2005 command prompt window.

csc /doc:<XMLfilename.xml> <CSharpfilename.cs>

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Predefined XML Tags

XML comments are inserted in XML tags. These tags can either be predefined or user-defined.

XML comments begin with three forward slashes (///)

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Constants

Constants are fixed values assigned to identifiers that are not modified throughout the execution of the code.

We have to initialize a constant at the time of its declaration.

The compiler can identify constants at the time of compilation because of the const keyword.

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Literals

A literal is a static value assigned to variables and constants

In C#, there are six types of literals

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Keywords

Keywords are reserved words and are separately compiled by the compiler.

They convey a predefined meaning to the compiler and hence cannot be created or modified.

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Escape sequence characters in C#

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Console Input/Output Operations

Two output methods: Console.Write() and Console.WriteLine()

These two methods accept parameters for formatting the text before the output is displayed Console.Write(“Customer name: {0}”, custName); Console.WriteLine(“Total amount: ${0:#,###.#0}”, totalAmount);

Two input methods: Console.Read() and Console.ReadLine() custName = Console.ReadLine();

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Convert Methods

The ReadLine() method can also be used to accept integer values.

The data is accepted as string and then converted into other data type by a Convert class age = Convert.ToInt32(Console.ReadLine());

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Format Specifiers

Format specifiers are special characters that are used to display values of variables in a formatted manner.

Some type of format specifiers Number Format Specifiers Datetime Format Specifiers

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Number Format Specifiers

We can convert numeric values in different formats.

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More Number Format Specifiers

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Datetime Format Specifiers

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More Datetime Format Specifiers

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Module 2 – Summary (1)

In C#, data types are also divided into two categories: value types and reference types

The predefined data types are referred to as basic data types in C#.

C# supports three types of comments XML comments are inserted in XML tags.

These tags can either be predefined or user-defined.

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Module 2 – Summary (2)

Two output methods: Console.Write() and Console.WriteLine()

Two input methods: Console.Read() and Console.ReadLine()

Convert class is used to convert a variable into another data type.

Some type of format specifiers: number and datatime