week 02 - hello world

8/2/2019 Week 02 - Hello World

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Copyright 1992 2005 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved.

Tutorial 2 - HelloWorld Application:Introduction to C++ Programming

Outline

2.1 Test-Driving the HelloWorld Application

2.2 Compiling and Running the Template HelloWorld Application

2.3 Introduction to C++ Code

2.4 Constructing the HelloWorld Application

2.5 Compilation Errors

2.6 Wrap-Up



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Objectives

In this tutorial, you will learn to: Read C++ code.

Write a C++ statement that displays a message on the screen.

Compile a C++ application. Execute an application.

Use escape sequences.

Locate and correct syntax errors.


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Copyright 1992 2005 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved. Copyright 1992 2004 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved.

Figure 2.1 Locating the completed HelloWorld application.

2.1 Test-Driving the HelloWorld Application(Cont.)


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Figure 2.2 Running the completed HelloWorld application.

2.1 Test-Driving the HelloWorld Application (Cont.)


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Copyright 1992 2005 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved. Copyright 1992 2004 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved.

Figure 2.3 Solutions can contain one or more projects.

2.2 Compiling and Running theTemplate HelloWorld Application

Projects

Large applications can contain many projects

Solutions


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Figure 2.4 New Project dialog. File > New > Project;

Title Bar(displaying NewProject )

Project Types: pane

Location of the newproject (yourlocation may bedifferent)

Templates:

pane

Description of project selected inTemplates: pane

2.2 Compiling and Running theTemplate HelloWorld Application (Cont.)

Default projectand solutionname


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Updated projectlocation

Updated projectand solution name

Browse button


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SimplyCppdirectory(selected)

Open button


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New HelloWorld Solution Folder

New HelloWorld Project Folder with C++ Source File


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New Solution Named HelloWorld

New Project Named HelloWorld

Figure 2.9 Solution Explorer window in Visual Studio .NET.

HelloWorld solution

HelloWorld project

Source Files folder



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2.2 Compiling and Running theHelloWorld Application (Cont.)

HelloWorld.cpp file (selected)

Download HelloWorld.cpp to your new HelloWorld ProjectFolder.

Right-click HelloWorld.cpp file and select properties.

Under General Tab uncheck Read-only. HelloWorld project folder


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2.2 Compiling and Running theHelloWorld Application (Cont.)

In Visual Studio Project Pane, right-click source folder and selectAdd Existing Item.


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Figure 2.11 Solution Explorer window after adding HelloWorld.cpp .

HelloWorld.cpp file



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HelloWorld.cpp file (selected)

HelloWorld project folder

Before Compiling Review

.vcxproj files

located in the HelloWorld Project directory

VC++ Project

Contains information regarding the project

2.2 Compiling and Running the Template HelloWorld Application (Cont.)

VC++ Project


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Compiling


Output Window


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After Compiling

Creates several files in multiple directories

Creates both object (.obj) and linked executable (.exe) files

.exe file is used to run application


Newly CreatedDebug folder (selected)



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After compiling, a newly created HelloWorld project Debug directorycontains the object file.

The Object file contains the Object code created by compiler.

Figure 2.13

HelloWorld Project directory after compilation.

Newly CreatedDebug folder (selected)

HelloWorld

project folder


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The Object file contains the Object (i.e., the Machine) code createdby the compiler.


Object File (selected)


Debug folder


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After compiling, the HelloWorld solution Debug directory contains the

executable file.


HelloWorld solution folder

Solution Debugfolder

Solution ( .sln ) file

HelloWorldproject


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Figure 2.14 Examining the contents of the Debug directory.


Newly created .exe file


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Running the application from Visual Studio

Run the application from the console window .


In addition to the application not producing any output,what is the difference?


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2.3 Introduction to C++ Code

Figure 2.16 HelloWorld applications C++ source code in Visual Studio .NET.


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2.3 Introduction to C++ Code (Cont.)

Comments Begin with two forward slashes // Improve readability Explain code

Full-line comments End-of-line comments

Compiler ignores comments

Figure 2.17 Examining comments in the HelloWorld applications C++

source code in Visual Studio .NET.

Full-line comments


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Preprocessor (i.e., Compiler Directives) Processes lines beginning with a pound sign #

Processed before the source code is compiled (pass 2)

Tells Preprocessor to include console window input/ output code Forgetting to include iostream in a program that uses input or

output is an error

Figure 2.18 Preprocessor directive (pass 1).

Preprocessor directive


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using directive

Specifies std (standard) namespace Accesses C++ Standard Library

Advance C++ feature. Allows names to be qualified You can find this variable name in this space (std) . Nice feature if name is

duplicated in another library. Analogy: Your first and last name. Typically you are only called

by your first name but to remove ambiguity, if required you maybe called by your first and last name.

Figure 2.19 using directive.

using directive


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Function main

Entry point of every C++ program

Returns an integer return

0 indicates successful termination

Figure 2.20 main function definition.

Function main header

Exiting the functionusing return


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Structure of function main Declare return type ( int etc.) Start with left brace {

Body of the function

End with right brace }


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C++ is case sensitive

Using incorrect capitalization for identifiers and keywords is anerror

C++ applications input / output data

Input

Certain C++ input comes from cin (standard input streamobject). cin >> myVariable ;

Usually tied to keyboard but can be tied to other devices

Output

Often output to cout (standard output stream object)cout


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Copyright 1992

2005 by Deitel & Associates, Inc. and Pearson Education Inc. All Rights Reserved.

2.4 Constructing the HelloWorld Application (Cont.)

Executable statement Compiler generates machine code to perform an action

Stream insertion operator


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2.4 Constructing the HelloWorld Application (Cont.) Operators

Special characters in C++ that perform operations

Binary and unary

Addition operator ( +), subtraction operator ( - ) andmultiplication operator ( * ) are examples of C++ operators

Unary operators

Operators that require only one operand such as the preincrementoperator ( ++ )

Binary operators

Operators such as multiplication ( * ) or division ( / ) that requiretwo operands to perform their operation

String

A sequence of characters


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In Section 2.4 your textbook has you run the Welcomeapplication using the start without debugging (shortcut ctrl -F5) command. This command is no longer supported inVisualStudio 2010. While you can turn the ctrl-F5 commandback ON , I will step you through some alternative solutions.
http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d6df1031-dd73-4683-b7d8-3252eb108439/


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Now Run the application from Visual Studio

Run the application from the console window .


Unlike running the application from the console windowVisual Studio simply opens the console window runs theprogram and closes it again. Lets look at some solutionsto this problem.


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In this solution we simply add #include to theinclude list and place getch(); just before the returnstatement. Include console I/O library

header file.

Insert getch() instruction without anargument.


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Build your solution (F7) and the start debugging(F5) .


Your Hello World message is displayed.

Press any key to run the return statement and close theconsole window.


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In this solution we add a breakpoint just before the returnstatement. Click here to turn Breakpoint

ON and OFF

A breakpoint tells the debugger to stop simulation of theprogram before running this line of code.

To set a breakpoint select the line and Debug > ToggleBreakpoint (F9) or simply click in the column where thebreakpoint is shown.


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Start debugging (F5) .


Your Hello World message is displayed.

Press any key to run the return statement and close theconsole window.


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Selecting Continue (F5) the simulation runs the return statementending the program and closing the console window.



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String literals

Compiler does not ignore whitespace characters

Splitting a statement in the middle of a string is a syntaxerror

Escape Sequences How you send a control character or a printable character

that is not on the keyboard.

Escape character is backslash \ Allows escape sequences to be read by compiler inside string

literals



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Escape Sequence Description\n Newline. Positions the screen cursor at the beginning of the next line.

\t Horizontal tab. Moves the screen cursor to the next tab stop.

\r Carriage return. Positions the screen cursor at the beginning of the current line; does not advanceto the next line.

\a Alert. Sounds the system bell.

\\ Backslash. Used to print a backslash character.

\" Double quote. Used to print a double quote character.

Figure 2 .23 Escape sequences.




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State ment O utputcout


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Stream insertion operators resume printing where previous statementhas stopped

When breaking up lengthy statements, choose logical break pointssuch as escape sequences, etc.

Figure 2.25 HelloWorld application using multiple stream insertion operators.

Multiple streaminsertion operators

Figure 2.26

HelloWorld application output. Note missing space .


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Figure 2.27 Inserting newlines.


Appending anewline todisplayed text


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HelloWorld.cpp (1 of 1)

HelloWorld applicationusing a newline character

Full line comments describe

the applications purpose

Include the header file

using directive providesaccess to the std namespace

Define the main function

Print a HelloWorldmessage

Exit the application


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2.5 Compilation Errors

Debugging

Process of locating and removing errors

Compilation errors

Compiler detects errors in code

Syntax errors

Logic Errors

Cause applications to produce erroneous results

Can be fixed using a debugger


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Figure 2.30 Output window listing a syntax error.

2.5 Compilation Errors (Cont.)

Missing semicolon at the end of

the statement preceding return


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Creating syntax errors Delete n in the last escape sequence in line 10 Capitalize r in return

Figure 2.32 Introducing two syntax errors into your code.

Two syntax errors


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Figure 2.33 Syntax error messages generated by the compiler.


Description of the errorsincluding file name and linenumber

Double-click line in the output window tohave marker placed next to the line withthe error in the source code


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Lab and Homework Assignment

Tutorial 2 HelloWorld Application. Turn in annotated source file with your own

comments. Answer and Turn-in Tutorial 2 Questions at the end of the Chapter. Always write

the question followed by the answer. Remember to highlight the answer .

Due next Wednesday

week 02 - hello world

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