C++InOneDayTheUltimateBeginnersGuideToC++With7AwesomeProjects

ByW.BEan

Copyright2016-AllRightsReserved–W.BEanALLRIGHTSRESERVED.Nopartofthispublicationmaybereproducedortransmittedinanyformwhatsoever,electronic,ormechanical,includingphotocopying,

recording,orbyanyinformationalstorageorretrievalsystemwithoutexpresswritten,datedandsignedpermissionfromtheauthor.

INTRODUCTION:

Manytimeswewonderhowcomputerscanworkfromtheinside.Fortheenduser,thereispracticallynointeractionwithsomethingdeeper.Theydonotneedtoknowmanydetailsabouthowthecomputerworksorsomethingaboutprogramming.Theenduserisonlyattractedbythefunctionalityandtheprogramtohaveasimpleinterfacethatiseasytohandle.However,thesoftwaredoesnotcreatebyitself.Somebodyhastodothedirtywork.Or,likeotherliketocallit,theartofprogramming.Themainpartofcomputersistheirmicroprocessor,thebrainthatexecuteseveryinstructionneededforeverytasktheuserneeds.Theseprocessoronlyunderstandsbinarycode(zerosandones)anditdoesnotknownothingaboutEnglishornumbers.So,howcanweinteractwiththeprocessor?Weuseprogramminglanguages.Throughhistory,manylanguageshavebeendevelopedfortheinteractionbetweentheprogrammersandthemachines.Inrecenttimes,programminghasbecomeamajorfieldofstudywithawidevarietyofprogramminglanguagetochoosedependingonthepurpose.OneofthemostpreferredlanguagesisC++.Why?Mainlybecauseofitsspeed,itsstandardsandthewiderangeofapplications.C++wasdevelopedasanimprovementfortheCprogramminglanguage.Thischangeaddedmanyfeatures,likeenablingobjectorientedprogramming,templates,memoryhandling,errorhandlingandmoretoolsfortheprogrammers.TheC++inonedayCourseistargetedforpeoplewhowanttolearnthebasicsoftheC++programminglanguage.Wewillcoverfromthemostbasicconceptsandstuff,perfectforbeginners,andasthecoursegoes,wewillbeaddingmorefeaturesfromthelanguageandalsostarttodevelopsomereallifeprojects.Thiscourseisdividedinfoursections:

1.ThebasicsofC++:Inthischapter,wewillcoverthebasicsofC++.Thisisthemaincoreofthecourseforbeginners.HerewewillcoverthebasicstructureforeveryC++program.Abriefexplanationofthelibrarysystem.ThestandardsystemofinputandoutputfromC++.Datatypesareanotherfundamentaltopictocoverandwillbediscussed,includingexamplesof

declaration,usingandstoringvalues.Stringprocessingwillbecovered.Inthischapter,wewillalsoexplainthebasicflowstructuresthatareusedinC++fordesigningsoftware.Theifstructure,theswitchstructure,thewhilestructureandtheforstructure.Finally,averybriefintroductiontothebasicsofobjectorientedprogramming.

2.ThingstodowithC++:Inthischapter,wewilldiscusswhatkindsofsoftwarecanbedevelopedusingtheC++programminglanguage.3.ImplementingprojectswithC++:Herewewillwritesomecode!7projectshavebeenselectedandprogrammedinordertoshowyouhowyoucandousefulthingswithC++.4.Whattodonext:Finally,wefinishthecoursewithsomerecommendationsontopicsthat,whilearenotverynecessaryforthebasics,theyareagoodplacetofollowafterlearningthebasics.Thesefeaturescanenableyoutodesignmoreoptimalandcomplexsoftware.

So,let’sgetstarted!

CHAPTER1:BASICSOFC++C++isamultipurposeprogramminglanguage.Whatisthis?Thatitcanbeusedforwritingeverytypeofsoftwarethattheprogrammerwants.Itcanbefromasimpleprogramlikecomputingthesumoftwonumbersuptoafulloperatingsystem(forexample,Windows)andvideogames(PS3,PS4,XBOX).SomeadvantagesthatC++hasoveritscompetitors(likeC#orJava)are,infirstplace,itsspeed.WhenyouwriteaC++program,itiscompiledtoabinaryfilethatrunsalongwiththeoperatingsystem.Second,itisstandard.C++hasaverywelldefinedstandardfrombeginningtoendandthismeansthat,iftheprogrammerwritescodeinstandardC++,itcanbeportedtoothercompilerswithminimumorsmallchanges.However,noteverythingisassimpleasitssounds.AlthoughC++isveryfast,itisverydifficulttomasterduetothelibrariesthatithasandtheStandardTemplateLibrary(STL)thatwillbediscussedinlaterchapters.Butlet’sgetstartedwiththebasicsofthelanguage.InstructionsandcompilerThroughthearticlewewillbeusingtheGNUC++compiler,G++,alongwiththeIDECodeLite.AllofthecodewillbewritteninstandardC++.CodeLiteandthecompilercanbedownloadedfromhttp://downloads.codelite.org/LibrariesThefullextensionofC++haslibrariesformanypurposes:inputandoutput,math,memorymanagement,time,fileprocessing,stringprocessingandmanymorefeatures.However,whenwestarttocode,wemustdefinewhichoftheselibrarieswewanttouseinourprogram.Since2003,C++alsoimplementedafeaturenamednamespaces,whichareanotherwaytoorganizeallofthestuffinsidethelanguage.ThemainfunctionInC++,allprogramsmustcontainafunction(orapieceofcode)namedmain.Thepurposeofthisfunctionistoindicatethecompilerwherewilltheprogramstartitsexecution.InputandOutput(I/O)AlmosteveryprograminC++needsaninputandanoutput.Therearesomeexceptionstotherule,butnormally,thereisalwaysI/O.Theinputisallthedatathatentersthecomputer,likenumbers,words.Theoutputarethedatathatisshowedtothescreen(alsonamedconsole).ThelibraryusedinC++forthisoperationsisnamediostream.Insideiostream,therearetwoobjectsthatwewillbeusingtoreaddatafromthekeyboardandshowingdatatotheconsole:coutandcin.

Beforeprogramminganything,inCodeLitewemustcreateanewproject.StepsforcreatinganewprojectinCodeLite:

Inthemainscreenyouwillseeabuttonwiththetext“NEW”.Clickit.Whenthenewwindowappears,selectontheleftsidetheoption“Console”andselect“Simpleexecutable(g++)”fromthelist.Ontherightpanelchooseanameforyourproject,forexample“Example1”.Inprojectpath,selectafolderinyourcomputerwhereyouwillsaveyourcode.Inthecompilersection,besuretohave“gnug++”selected.ClickOK

Afterdoingthis,gototheleftsideofyourscreenandwillfindafolderwiththenameyouselectedforyourproject.Openitandyouwillseeanotherfoldernamedsrc(abbreviationforsource).Insidesrc,therewillbeafilenamedmain.cpp.ThisisthefilewhereyouwillwriteyourC++code.TheexamplecodeforasimpleinputandoutputinC++isasfollowing:#include<iostream>usingnamespacestd;intmain()

{

cout<<"ThisismyfirstC++program";return0;

}

Asyoucanappreciate,thefirstlineweincludedthelibraryforI/O.Onthesecondline,usingnamespacestdwesaytoC++thatwewanttouseallofthefeaturesinsidetheselectedlibraries(likecout).Afterthis,wefindourmainfunction.Hereiswherealltheexecutionbegins.AllfunctionsinC++haceanopeningandclosingbracethatindicateswherethefunctionstartsandends.Insidemain,thereisthelinecout<<“ThisismyfirstC++program”;Thislinewilloutputeverythinginsidethedoublequotestotheconsole.Noticethatthislineendswithasemicolon.InC++,alltheinstructionsinsideablockofcodeendwithasemicolon(therearesomeexceptionsthatwillbecovered).Youcanseethatbetweenthecoutobjectandourtext,therearetwo<signs.Theyarenamedoverloadedoperatorsandtheyrepresentthedirectionwheretheinformationistraveling,inthiscasetheinformationisgoingoutsidethecomputer.Asyoumaythink,whenwewanttomakeaninputtotheprogram,wewillbeusingthe>>operators.Forexecutingtheprogram,gototheBuildmenuandselecttheoptionBuildandRunproject.Youwillseehowablackscreenappears.Thisistheconsoleandthisiswherewewillperformourinputandoutput.PausingtheexecutionIftheconsoleappearsandimmediatelycloses,don’tworry,itisnormal.Butweneedtoseetheoutput.Forthis,add:cin.get()Beforereturn0;DataTypesandvariablesWhenweworkwithaprogram,therearemanytypesofdatawecanuse.Forexample:numbers,text,and

somespecialtypesofdata.AllofthesearecalledDataTypes.TheyareveryimportantinC++becauseitisthemainpointfordevelopinginputs.InC++wehave3categories:numeric,alphabeticandbinary.Inthenumericcategorywehave3typesofdata:

int–Representintegernumbersfloat–Representsnumberswith7decimalpositionsafterthepointdouble–Representsnumberswith15/16decimalpositionsafterthepoint

Therearemorespecificnumericdatatypesbutforthepurposesofthisarticle,thesethreeareenough.Forthealphabeticcategorywehavetwotypesofdata:

char–Storeonealphanumericdigitstring–Storeasequenceofalphanumericdigits

Andinthebinarycategory,thereisonlyonedatatype:bool–Storeatrueorfalse.ZeroorOne.

Thebooldatatypemaysoundveryuselessatfirstbutithasitshandyapplicationswhenprogrammingsomespecificroutines.But,whydoweneedallofthesetypes?Simple:InC++thereisaconceptnamedvariable.Avariablecanstoreinformationofanyofthesementionedtypes.Imagineavariablelikeaboxthatcanholdsomevalueforacertaintimeandyoucandoanyoperationwiththatvalue.InC++,beforeusingvariables,wemustdeclarethem.How?Likethis:<datatype><nameOfVariable>Let’smakeasimpleexample.Wewanttocalculatethesumoftwonumbers.Thesenumbersareinteger.So,inordertoaccomplishthis,wemustdeclarethreevariables,oneforeachnumberandanotheronefortheresult:intnumberA;intnumberB;intresult;Asyoucansee,foreachvariablewedefinedtheinttypeandafterthedatatype,thenameforthevariable.Youcannamethevariablesinthewaythatyouwant,butitisrecommendabletogivethemanamesimilartotheuseitwillhave.Nowthequestionis:Howcanweassingavalue?Weusetheequal=operator:numberA=10;numberB=5;result=numberA+numberB;Forthis,Iassigned10tonumberAand5tonumberB.Afterthat,weassignedthevalueofresulttothesumofbothvariables.Thecompleteprogramwouldlooklikethis:#include<iostream>usingnamespacestd;intmain()

{

intnumberA;intnumberB;intresult;numberA=10;

numberB=5;result=numberA+numberB;cout<<result;cin.get();return0;

}

Noticethathere,weusedcout<<result;forouroutputwithoutthedoublequotes.Whenyouusedoublequoutes,ALLthetextinsidethequoteswillgodirectlytothescreen.However,whenwewanttodisplaythevalueofavariable,wemustwritethenameofthevariablewithoutquotes.C++thenwilllookforthevalueinsidethevariableandshowitonyourscreen.Therearesomelimitationstothiscode.Forexample:wehavetoassignvaluesdirectlyinsidethecodeforthesum.Theoptimalwaywouldbegivingtheusertheoptionforinputthevaluesintotheprogram.Thiscanbedonelikethis:#include<iostream>usingnamespacestd;intmain()

{

intnumberA;intnumberB;intresult;cout<<"Enterfirstvalue:";cin>>numberA;cout<<"Entersecondvalue:";cin>>numberB;result=numberA+numberB;cout<<"Thesumofbothvaluesis:"<<result;cin.get();return0;

}

Noticesomedifferencesinrelationtotheothercode.First,thedeclarationofthethreevariablesweneed.Afterthis,wetelltheusertoenterthefirstvalue.Wecanseehowcin>>numerAisused.Withthisline,wetellC++tocapturetheinputfromthekeyboardandthevalueassignittothevariablenumberA.ThesamefornumberB.Afterthis,theresultofthesumiscalculatedandissenttotheoutput.Noticehowinthelastoutput,theoverloadedoperationappearstwice.Thisisveryconvenientwewanttoshowmultiplevaluesinthesameline.

Now,let’ssaywewanttoknowtheaverageofthesetwovalues.Wecanmodifytheresultlineinthefollowingway:result=(numberA+numberB)/2;Theparenthesisindicatesthatthemathematicaloperationsinsidetheparenthesiswillbedonefirstly.Afterthat,itwillcontinuewiththerestoftheexpression.However,wehaveaproblemwiththisline.SupposenumberAhasthevalueof5andnumberBhasavalueof6.Theresultwouldbe5.5.Noproblemhereuntil…wenoticethatresultisdeclaredasint.And,accordingtoourdatatypes,theintdatatypeisreservedonlyforinteger.So,whatshouldweuse?Wemustchangethedatatypeofresulttoeitherfloatordouble.doubleresult;Besidessumanddivition,therearemoremathoperatorstoperformoperations.Thesustractionisperformedwiththe“-“operator,theproductisperformedwiththe“*”operator.Andaspecialcaseisthe“%”operator,namedModulus.Themoduluswillreturntheleftoverofadivision.MorecomplexmathemathicaloperationscanbeperformedwithC++usingthe<complex>library.Porexample,power,squareroot,trigonometricalfunctions,andmore.

StringI/OThemanagementofstringinC++canbedonewiththelibrary<string>.Itincludestheobjectstringthatweneedtouse.Forexample,let’ssupposewewantaprogramtosaygoodbyetoanyone.Itwouldlooklikethis:#include<iostream>#include<string>usingnamespacestd;intmain()

{

stringname;cout<<"What'syourname?";cin>>name;cout<<"Goodbye"<<name;cin.get();return0;

}

Thefirstthingyoumaynoticeisthatweaddedthestringlibrary.Insidemain,justlikeanyvariable,wedeclarednameasstringtype.Afterthat,werequestedtheusertowritetheirnameandthenoutputthesentence“Goodbye”followedbythegivenname.Let’sseeanotherexample:#include<iostream>#include<string>usingnamespacestd;intmain()

{

{

stringname;stringlastname;stringfullname;cout<<"What'syourname?";cin>>name;cout<<"Andyourlastname?";cin>>lastname;fullname=name+""+lastname;cout<<"Goodbye"<<fullname;cin.get();return0;

}

Inthiscode,Ideclaredacoupleofextrastrings.Wealsorequesttheusertheirlastname.Inprogramming,wecallconcatenatetotheactionofattachstrings.Inthisexample,weconcatenatename,anemptyspaceandlastnametoproduceauniquestringcontainingthefullname.Andthatstringissenttotheoutput.ScapeSequencesThisisanadditiontotheI/Otopic.InC++,therearespecialsequencesthatallowtheprogrammerabetterdistributionoftheinformationthatisdisplayed.Thesequencesare:

\n–Endofline\t–Insertionoftabularspace

Withthesetwosequences,youcandesignawelldistributedinterface.Lookattheexample:cout<<“Hereisaline\n”<<“Hereisanotherline\t”<<“Iamafteratabspace”;Thisisasimpleexampleofthesequencesandcanbeusedonlywiththecoutobject.ProgramFlowUpuntilthispoint.Wehavecoveredthetypesofdata,howtoshowinfotothescreenandcapturingdatafromthekeyboard.Now,averyimportantpartofC++aretheflowcontrolinstructions.Withthispart,youwillbeabletotakedecisionsandmakecomplexprograms.IfStructureTheifisaconditionalstructure.Likeitsownnamesays,ifsomethinghappens,thendothisthing.Thestructuregoesasfollow:if(condition)

{

//dosomething

}

Theconditionisaexpressioninwhichtheresultwillbetrueorfalse.Therearesomeoperatorstoevaluatethecondition:

EQUALS(==):Willbetrueifbothvaluesarethesame.Example:a=bAND(&&):Willbetrueifallvaluesaretrue.OR(||):Willbetrueifanyofthevaluesaretrue.NOT(!):Willbetrueifthevalueisfalse.GREATER(A>B):WillbetrueifAisgreaterthanBLESS(A<B):WillbetrueifBisgreaterthanA.

Let’ssupposewemustevaluateifastudentapprovedornotacourse.Lookathefollowingcode:#include<iostream>usingnamespacestd;intmain()

{

intnote;cout<<"Enteryournote:";cin>>note;if(note>6)

{

cout<<"Congratulations.Youpassed!";}return0;

}

Weasktheuserfortheircoursenote.Iftheuserentersanumbergreaterthan6,thentheflowoftheprogramentersthecodeblocksurroundedbythebraces.Ifnot,itignoresthisblockandcontinuesitsexecution.NoticethattheIFinstructiondoesnotendwithsemicolon.Thisisbecauseitisfollowedbyablockofcode.But,whathappenswhenthenoteislessthansix?Weusetheelsekeyword.#include<iostream>usingnamespacestd;intmain()

{

intnote;cout<<"Enteryournote:";cin>>note;if(note>6)

{

cout<<"Congratulations.Youpassed!";}else

{

cout<<"Sorry.Youdidnotpassed";}return0;

}

Thiscodeisexactlythesameasthelastonewithonedifference.Weaddedtheelsekeywordwithitsrespectiveblockofcode.First,theconditionnote>6isevaluated.Ifthisconditionistrue,thentheblockofcodenexttotheifwillbeexecutedandtheelseblockcodewillbeignored.Iftheconditionisfalse,thentheifblockcodewillbeignoredandtheelseblockcodewillbeexecuted.Wecanalsoaddmultipleconditionsintheifclause.Lookatthefollowingcode:if(note==10)

{

cout<<"Excellent!";

}

elseif(note>6&&note<10)

{

cout<<"Congratulations.Youpassed";}else

{

cout<<"Sorry.Youdidnotapprove";}Weaddedsomethingcalledelseifanditallowstheprogrammertoaddmultipleconditionsonthesameif.Inthisexample,ifnoteequalstoten,onlythefirstblockofcodeisgoingtobeexecuted.Onthesecondcontidion,ifnoteisgreaterthansixANDnoteislessthan10,thenthemiddleblockofcodewillbe

executed.Youcanaddasmanyelseifasyoumaywantorneed.However,ifneithertheIFnoranyoftheELSEIFconditionsaretrue,thentheELSEblockofcodewillbeexecuted.TheelseisonlyexecutedwhennoneoftheIForELSEIFaretrue.MakingeasiermultipleconditionsYoumightthink“Hey,whatifIhavealotofconditions,like20or30?Itwillbealotofcode”andyes,youareright.Itwoulddefinitelybealotofhardworkhavingmanyconditions.ButC++hasaanswerforthis:theswitchinstruction.Withswitch,wecanusemultipleconditionsinasimpleway.Continuingthesameexampleofthenotes,let’ssupposewewantadifferentmessagefortheapprovingnotes.Startingfromsix,therewillbe5differentmessagesforapprovingandasinglemessageforfailing.Usingtheswitchstatement,thecodewouldlooklikethis:switch(note)

{

case10:cout<<"Excellent";break;case9:cout<<"Verygoodnote";break;case8:cout<<"Goodjob!";break;case7:cout<<"Notbad.Keepworking";break;case6:cout<<"Youpassedbyabit";break;default:cout<<"Youdidnotapprove";}Thefirstthingtowatchisthatthevariablewewanttocomparegoesinsidecurlybracesnexttotheswitchstatement.Itdoesnotneedtoendwithsemicolonbecauseitisfollowedbytheblockofcodefortheswitch.Foreachcomparison,weusethecasekeywordfollowedbythevaluewearelooking.Incasenotehasavalueof10,themessage“Excellent”goestotheoutput.Foreachcase,wemustaddthebreakkeyword.Ifwedonotdothis,theswitchstatementwillfalltothenextcaseuntileitherfindsabreakortheendoftheswitchcodeblock.LoopsAlright,soyounowknowhowtotakedecisionsonyourprogram.Youcandirecttheflowtoanotherpiecesofcodeanddecidewhichoneexecuteandwhen.Excellent.Let’ssaythatyouwanttocalculateanaverage.Eachstudentistaking5subjectsandyouwanttoknowtheaverageofthosenote.Simple,yousumthemupanddivideby5.But,thereisnotonestudentontheschool.Canyoucopythecodeandrepeatthis10or15times?Well..yes,youcoulddoit,butthecodewouldstartbeingveryunmanageable.So,howcanwefixthisproblem?C++hastherighttoolforthejob,anditiscalledloops.Aloopisablockofcodethatwillrepeatitselfuntilaconditionissatisfied.Wehavetwokindsofloops:countingloopsandconditionalloops.Thefirstoneiscalledforanditisusedwhenwealreadyknowhowmanytimeswewanttorepeattheblockofcode.Thesyntaxfortheforloopislikethis:for(VARIABLES;CONTIDION;INCREMENT)

{

//Repeatsomecode

}

Thesecondisnamedwhile,anditwillloopuntilsomeconditionissatisfied.Thesyntaxlookslikethis:while(CONDITION)

{

//Repeatsomecode

}

Followingtheexampleoftheaverages,calculatingtheaveragefor10studentswilllooklikethis:floatnote1,note2,note3,note4,note5;floatavg;for(inti=0;i!=10;i++)

{

cout<<"Firstnote:";cin>>note1;cout<<"Secondnote:";cin>>note2;cout<<"Thirdnote:";cin>>note3;cout<<"Fourthnote:";cin>>note4;cout<<"Fifthnote:";cin>>note5;avg=(note1+note2+note3+note4+note5)/5;cout<<"Average:"<<avg<<"\n";}Asyoucansee,wedeclaredthevariablethatwearegoingtouseoutsidetheloop.Afterthis,wedeclaredavariablenamedi.Iisthecounteranditwillbeincrementedeveryloop.Lookatthedeclaration:itstartsatzero.Ontheconditionsection,theoperator“!=”meansdifferent,so,theloopcontinuewhileuntilIequalsto10(thatmeans,10times).Afterthis,gototheblockofcode.Theprogramaskstheusertoenterfivenotes.Don’tworryaboutcoutandcinonthesameline,thatistheuseofthesemicolon,separatingsentences.Afterthefivenotesareinside,theaverageiscalculatedandshowntothedisplay.Whenwereachtheendoftheblockthecode,wegobacktotheincrementandInowequalstoI+1.The++operatormeansthatthevariableisincrementedbyone.Withthispieceofcode,wecanruntheloopfor10times.But,let’ssaywewanttotelltheloophowmanystudentsareontheschool,notjustanantiquated10-times-run.Itcouldbethisway:intlimit;cout<<"Howmanystudentsareinyourschool?:";cin>>limit;for(inti=0;i!=limit;i++)

{...}

Here,wedeclaredanothervariablenamedlimit.ThatnumberisobtainedfromthekeyboardandtheloopwillcontinueuntilIequalstolimit.Asyoumightobserve,wemustalwaysknowwhentheloopisgoingtoend(either10oravariable).But,howwedowhenwedonotknowhowtostop?Thisisasituationwhenthewhileloopisveryuseful.Let’ssayyouwanttocalculatetheaverageBUTyoudonotknowhowmanysubjectstheschoolhas.Justkeeptheprogramrunninguntilyoutolditto.Thiscouldbeaveryrealsituation.Andwecannotaskthestudent.So,lookatthispiece:intval=1;while(val==1)

{

cout<<"Firstnote:";cin>>note1;cout<<"Secondnote:";cin>>note2;cout<<"Thirdnote:";cin>>note3;cout<<"Fourthnote:";cin>>note4;cout<<"Fifthnote:";cin>>note5;avg=(note1+note2+note3+note4+note5)/5;cout<<"Average:"<<avg<<"\n";cout<<"Doyouwanttocontinue?[1]YES.[Other]NO";cin>>val;

}

Thiswouldbereadasfollow:“Whilevalueisequaltoone,executethiscode”.Whendoesvalchangesitsvalue?Attheendoftheblockofcode,whereweasktheuserifhewantstocontinueornot.Ifheselectsone,valcontinueshavingaone.Anythingelsewillresultontheterminationoftheloop.InfiniteloopsandexitsSometimesit’sveryusefultohaveinfiniteloops.Thiswillnotbemuchcoveredbutitisgoodtoknowhow.Inthewhileloop,its:While(true)

{

//Dosomething

}

Fortheloopfor:for(;;)

{

//Dosomething

}

Thekeywordusedforendingtheloopsisbreak(yes,theonefromswitch).Itcanbeusedlikethis:while(true)

{

if(somethingHappens)

{

break;

}

}

StructuredDataandObjectOrientedProgrammingUpuntilthispoint,allthevariableswehaveusedaresingle,thedonotrepresentmuchofstuff,justavalue.Butinprogramming,therearecertainprogramsthatneedtobesolvedinadifferentwayofthinking.Thisiswhereobjectorientedprogrammingbeginsitsexistence.Youmayhavealreadyheardofthis.Intheprogrammingwehaveseen,doyouimagenhowcanyourepresentabook?Apen?ACar?Howcantheyinteractbetweenthemselves?It’sdifficult.So,Iwillintroduceyoutotheclass.Aclassisadesign(ortemplate)ofsomethingthatexistsinreallife.Don’tworry,it’sbuildwiththesamedatatypeswehaveseen.First,wewillrepresentaclassfromabook:classBook

{

public:stringtitle;stringauthor;intyear;intpages;

};

Thefirstthingisthewordclassfollowedbythenameofthethingwewanttodescribe.Insidethebraces,therewillbethepropertiesoftheclass.Why?Let’sputisinthisway:Whatdatacanweobtainfromthebook?Well,itstitle,theauthor,inwhatyearwaspublished,howmanypagesdoesithas.Noticehoweachpropertyhasitsowndatatype.Stringfortitleandauthor(becausetheyarecharacters)andintegerforyearandpages.Aftertheendoftheclass,DONOTFORGETTHESEMICOLON.

Now,let’sputittogetherinasampleprogram:#include<iostream>#include<string>usingnamespacestd;classBook

{

public:stringtitle;stringauthor;intyear;intpages;

};

intmain()

{

BookmyFavoriteBook;BookmyLeastFavBook;myFavoriteBook.title="BeginningC++";myLeastFavBook.title="Idontremember";cout<<"Myfavoritebookis"<<myFavoriteBook.title<<"\n";cout<<"Ireallydontlike"<<myLeastFavBook.title<<"\n";cin.get();return0;

}

Here,wedeclareourfavoritetypeasadatatypeBOOK.Afterthis,wecanaccessthemembersofthatobjectusingthe“.”operator.Afterthepoint,wehaveaccesstoallthepropertiesfromtheobject.Although

bothbooksarefromthesameBOOKclass,eachonehasitsownseparatedsetofproperties.

CHAPTER2:TYPESOFTHINGSTOBUILDWITHC++

TherearemanykindsofthingstobuildusingC++.Asmentionedbefore,C++iswellpreferredforitsefficiencyandspeedofexecution.C++isamultipurposeprogramminglanguage.Thatmeansthatitcanbeusedtoprogramliterallyeverything.Thereareotherlanguagesthatare“purposespecific”,forexample,theRprogramminglanguageisforstatistics,orMATLAB,thatisusedformathandmatrixes.ThekindofthingsthatcanbebuiltusingC++literallydependsontheimaginationandcreativityoftheprogrammer.Herewewilllistsomeofthem.SecurityThinkforamomentfortheantivirusyouhaveinstalled(andifyoudon’thaveanyinstalled,anywaythinkofit).Itmustbeveryfastforsearchingandinspectingfiles(atbinarylevel),havefirewalls,internetconnectivityandagoodcommunicationwiththeoperatingsystem.TheonlylanguagethatcanmeettheserequirementsisC/C++.ThefeaturesofC/C++enablestheprogrammertoprogramatlowlevel(binaryandassembly)forthemostcomplicatedworkandalsoworkatthehighlevel(theAPIsusedtocommunicatetoWindows).VideogamesYes,C++maybeoneofthemost(orprobablythemost)preferredlanguagestowritevideogames.Itsspeedatperformingmathematicaloperationsgivesitaprettyniceadvantageoveritscompetitors.TherunnerupisC#.Andnotonlyvideogames,alsosomebackenginemotorsareprogrammedinC++,likeUnrealEngine.ItisdevelopedalmostallinC++(therestinassembly).And,Ibelievethatthisoneisevenharderbecause,ifyouhavealittleknowledgeonvideogamedevelopment,UnrealEngineisusedforcreatingvideogames.Examplesofthemare:TomClancyRanbowSixVegas,GearsofWar2&3&4,DeadIsland2,MassEffect2,BioShock,Assassin’sCreedChroniclesTrilogyandIamonlymentioningthefamousones.AndthesearemadeusingUnrealEngine.OperatingSystemsThisoneisveryhardtoexplain.Imagineafulloperatingsystem:booting,libraries,peripherals,APIs,memorymanagement,filesystem,commandline,

andgraphicaluserinterface,everythingyouneed.Obviously,someofthelowestpartsofanoperatingsystemcannotturnthebacktoassemblylanguage,buttherestcanbemanagedusingonlyC++.Examples:well,Windows95,98,2000andXP.Apparently,WindowsVistahadbothC#andC++andthatwassomeofthereasonsofitspooreffiency,afterthat,MicrosoftusedcompletelyC#.Anotherone:MacOSX.AnotherprogramminglanguageItsoundkindofstrange.Youmightthink“HowcananotherlanguagebemadeusingC++?”Wellyes,itcanbedone.ItisnoteasybutindeedcanbeaccomplishedwithsomeprogrammingskillsandsomeofCompilersTheory.GuesswhatlanguagewasmadeusingC++?Java.Beingalittlebitmoretechnic,theJavaVirtualMachine(theboxthatexecuteseverythingJavaneedregardlesstheoperatingsystem)wasmadeusingC.But,C++inheritsallofthefeaturesofCplusitsownSTL,memorymanagementandmanymoretools.Thesamestorygoestopython.Pythonisaninterpretedprogramminglanguageandnotacompilationprogramminglanguage.Whatthismeansisthatthecodeisexecutedbyaninterpreter,ratherthantheoperatingsystem.Inpythontherearenoexecutables,onlyscripts.ButIwillletyouguessinwhatlanguagewaswrittentheinterpreter?Yes,that’sright.Inconclussion,youcandevelopwhatevercomestomindusingC++,it'sjustamatterofcreativity.

CHAPTER3:PROJECT#1CALCULATOR

ThisprojectwillfocusontheuseofthemathtoolsthatC++hasforperformingmathcalculations.Lookatthiscode:#include<iostream>#include<cmath>usingnamespacestd;Here we define our headers. The <cmath> header is the one that has thefunctions thatC++usesfor themathoperations.It isanoriginalClibrary thatcanbeusedalongwithC++.Ourcalculatorwillhavefourkindsofoperations:arithmetical,trigonometrical,exponentialandlogarithmic.Inourmainfunctionwe’llhavesomethinglikethis:intmain()

{

intsel=0;cout << "ADVANCED CALCULATOR\n"; cout << "ENTER THE TYPE OFOPERATION YOUWANT TO CALCULATE\n"; cout << "[1] Arithmetic\n";cout << "[2] Trigonometric\n"; cout << "[3] Exponential\n"; cout << "[4]Logarithmic\n";cout<<"Yourchoice:";cin>>sel;switch(sel)

{

case1:arithmetic();break;case2:trigonometric();break;case3:exponential();break;case4:logarithmic();break;default:cout<<"invalidoperation";}return0;

}

Herewedefineourmenufortheusertoselectthekindofoperationitwantstoperform.Thisoperationisstoredintheselvariable.Afterthis,wetelltheuserthedifferentkindsofoperationalongwiththevaluethatmustbeentered.Thevalueforselwillbeusedtocontroltheflowoftheprogramascanbeseen

on the switch statement. Only applies for values between 1 and 4. Withsomethingdifferentthanthistheprogramwillend.voidarithmetic()

{

intop=0;floatA=0;floatB=0;cout << "Select operation\n"; cout << "[1] Addition\n"; cout << "[2]Substraction\n";cout<<"[3]Product\n";cout<<"[4]Division\n";cin>>op;cout<<"Enterfirstnumber:";cin>>A;cout<<"Entersecondnumber:";cin>>B;cout<<"Result:";switch(op)

{

case1:cout<<(A+B);break;case2:cout<<(A-B);break;

case3:cout<<(A*B);break;case4:cout<<(A/B);break;default:cout<<"Invalidoperation";break;

}

cout<<endl;

}

In the arithmetic function, we request another time the user what kind ofoperationwants to perform,This section is only for the four basic operations.Heretheuserentersthekindofoperationandbothoperators.Aftertheprogramknows this data, it can perform the opration and show it to the screen.At theend,thecontrolflowreturntomain.voidtrigonometric()

{

intop=0;floatval=0.0;cout << "Select\n"; cout << "[1] Sine\n"; cout << "[2] Cosine\n"; cout <<"Op:";cin>>op;cout<<"Entervalue:";cin>>val;if(op==1)

{

cout<<sin(val);

}

elseif(op==2)

{

cout<<cos(val);

}

else

{

cout<<"Invalidoperation";}cout<<endl;

}

Withthetrigonometricalpart,isalmostthesame,butheretheusercancalculatethesineandcosinefunctions.Theusergives thevalueand theprogramreturntheresult.voidexponential()

{

floatbase=0.0;floateee=0.0;cout<<"Enterbase:";cin>>base;cout<<"Enterexpnent:";cin>>eee;cout<<pow(base,eee)<<endl;}Theexponentialpartcalculatesanyoperationfromx^n.Heretheuserentersthebaseandthepowerand,C++,usingthepow()functions,calculatesthevalueanddisplaysit.voidlogarithmic()

{

floatvalue=0.0;cout<<"Entervalueforcalculatethelog(e):";cin>>value;cout<<log(value)<<endl;}Logarithmic section is almost the same but calculates the same but here, itcalculatestlee-basedlogarithmofthedatathattheuserinputstotheprogram.

CHAPTER4:PROJECT#2:AGENDA

Forthisproject,wewillsimulateaphoneagenda,liketheoneyouhaveinyourhouseandusethemtokeeprecordofalltheimportantnumbersyouneed,butwewilldoitusingC++.Foreachcontact,theirnameandtheirphonewillbestored(althoughyoucanaddasmanyfieldsasyouwant).Also,wewillbeusinganewandverypowerfulfeatureoftheStandardTemplateLibraryofC++:vector.

Usingvectors

Imaginethisphoneagendawillhavemorethan100phonenumbers.Areyougoingtodeclare100variablesforthenumbers?Andanother100forthenames?Ofcoursenot.Hereiswherevectorfitsperfectly.Withvector,youwillbeabletoinsertasmanyelementsasyoulike.ForusingvectorinsideC++,wemustaddthelibrary<vector>inourcode.Wewillalsoneediostreamandstring.

So,ourlibrarieswillbe:

#include<iostream>

#include<string>

#include<vector>

usingnamespacestd;

Afterthenamespacestd,wearegoingtodeclareourvector.Thewillgooutsidethemainfunction.Bydeclaringanyvariableoutsidemain(oranyfunction)it

meansthatthisvariablewillbeglobal.Inotherterms,anyonehasaccesstothemforreadingandwriting.Lookcloselyatthesyntax:

vector<string>Names;

vector<string>Phones;

Thewordvectorobviouslysaysthatthesevariableswillbevectors,butnow,lookinsidethesigns.

Thereisthewordstring.Withthis,wetellC++thatourvectorswillcontainonlystrings.Wecanonlyhavevectorsofints,ofstring,orany.Youcannotmixdatatypesinasinglevector.Now,wewillwriteourmainfunction.Duetothenatureofourprogram,weneedtobeabletonavigatethroughitssections.Theprogramwillhavethreesections:addacontact,searchforacontactusingitsIDandsearchforacontactusingtheirname.Foraccomplishthis,wewilluseamenuthatwillgiveusthesethreeoptionsandalsoanexitfromtheprogram.

Themainfunctionwouldlikethefollowingcode:intmain()

{

intsel=0;

while(true)

{

cout<<"MyAgenda++\n\n";

cout<<"Chooseanumbertoexecuteanoption\n\n";cout<<"[1]NewContact\n";

cout<<"[2]SearchbyID\n";

cout<<"[3]SearchbyName\n";cout<<"[4]Exit\n";

cout<<"Yourchoice:";

cin>>sel;

switch(sel)

{

case1:

case2:

NewContact();

break;

SearchByID();

break;

SearchByName();

break;

case3:

}

if(sel==4)

{

break;

}

}

return0;

}

Weonlydeclaredasinglevariable,namedsel.Sel(forselection)willbeusedforthechoicethattheuserselectsatthemenu.Afterthedeclaration,youcanseehowwedeclaredaninfiniteloopusingwhile(true).Whydoweneedanendlessloop?Becausetheprogramwillcontinueitsexecutionuntil..well,wedon’tknow.Insideourloop,therearethecoutlines.Inhere,weshowalittletitletotheuser,“Agenda++”followedbytwolinejumps.Andthefourfollowingcoutsareusedfortellingtheuserthattherearefourdifferentchoicesintheprogram.Byselectinganyoneofthese,theprogramwillknowwheretogo.Nexttothis,welefttheprogramtotheuser,wherehewillintroduceitsselections.

Thatselectionfallsintotheswitchstatement.Iftheuserselects1,theprogramwillgointotheNewContact()function.

FunctionsInC++areawayofmodelingtheprogram.Notallthecodeiswritteninsidethemainfunctionbecauseitwouldbeverydifficulttofollowandalsotoimaginehowallofthepieceofcodeconnectthemselves.Instead,wedividetheprogramintosmallmodules,whereeachonetakescareofasingletask.

Importantnote:Inthecode,themainfunctionmustbethelastfunction.Writeallofthefollowingfunctionsinlinesbeforemain.

Inthisexample,thefunctionNewContact()hasthejobtorequesttheusertogiveanewnameandanewphone,likethis:voidNewContact()

{

stringname;

stringphone;

cout<<"\n\nEnteranameforthecontact:";cin>>name;

cout<<"Enterthephoneforthiscontact:";cin>>phone;

cout<<"TheIDforthiscontactwillbe"<<Names.size()<<"\n\n";

Names.push_back(name);

Phones.push_back(phone);

}

Lookhowthefunctionstarts,itisverysimilartothemainfunction.Thewordvoidmeansthatthisfunctiondoesnotreturnanything(rightnowmaysoundconfusing,butyou’llgetitsoon).Afterthebraceiswherethefunctioncodeactuallystarts.Thefirstthingwedoistodeclareacoupleofstring,onenamednameandtheotheronephone.Thesestringwillbeusedfortheinputfromtheuser.

Werequesttheusertoenterthenameandthephoneforthenewcontact.Nowthatwehaveit,wemustassingthiscontactitsIDnumber.Rememberclasses?Thevectorcontainsapropertynamedsize(),whichtellsushowmanyelementsdoesthevectorholds.Inthiscase,weassigntheIDasthecurrentsize.

Afterthat,weuseanothergreattoolfromvector,actuallythemostbasicone:pushback.Imagineavectorlikeadeckofcards.Thefunctionpushbackwilladdanewelementatthebackoftheactualdeck.

Forthisexample,weaddattheendofournamevectorthevaluethattheuserentered.Thesamethingforthethephones.Andnowwehavebothvaluesinourvectors.

Nowthatwehaveourfunctionforinsertingvalues,weneedtoretrievethemfromtheirstorage.

Thatiswherethefunctionsforsearchwillbeimplemented.Asmentionedbefore,wewillusetwotypesforsearchingvalues:oneusingtheIDofthecontactandtheotheroneusingthename.

FortheID,ourfunctionwillbelikethis:voidSearchByID()

{

intvalue;

cout<<"\n\nEntertheIDofthecontacttosearch:";cin>>value;

if(value>=Names.size())

{

cout<<"ThisIDdoesnotexist\n\n";return;

}

cout<<"Informationforcontact"<<value<<"\n";cout<<"Name:"<<Names[value]<<"\n";cout<<"Phone:"<<Phones[value]<<"\n";}

Again,firstoffeverything,wewritethefunctionname,inthiscasewillbeSearchByID.Afterthis,thevariablevaluewillcontainthevaluethattheuserwantstosearch.Beforemakinganysearch,wemustassurethatthisvariableiswithingrangefromourvector.Whatdoesthismeans?Well,supposewehaveavectorwith5elementsandtheuserinputsthenumber8.Whatshouldwedo?

Wealreadyknowthatourvectoris5elementslong,so,ifthenumberthattheuserentersinthesearchisequalorgreaterthanthesizeofourvector,thenitwillbeofrange.

Thisisimplementedusingtheifshownonthefunction.Ifthiscertainconditionoccurs,itwillshowamessageonourprogramstatingthat“ThisIDdoesnotexist”followedbythereturnkeyword.

Thefunctionofreturnistoterminatethefunction.InordertoNOTexecuteanysearch,wemustexitthefunctionbeforeitreachesthenextcode.Becauseofthis,thereturnkeywordisaddedandafterthecoutinsideourcondition,thefunctionimmediatelyendsandreturntothemainfunction.

Ifthevalueenteredbytheuserisavalidone,then,itwilllocatetheinformation.Noticehowinthelasttwocoutsweusethe“[]”operator.Thisiscalledanindexanditisusedtodifferentiatevalueswithinthevector.Itgoesfrom0uptosize()-1.

Let’ssupposethattheuserentersfornamethevalues:John,Michael,Sean.And

forthephones:111111,333333,555555.Then,ourvectorswouldbelikethis:Names=John,Michael,Sean

Phones:111111,333333,555555

Ifwewanttoretrievetheinformation,Names[0]wouldbeJohn;Names[1]wouldbeMichaelandNames[2]wouldbeSean.Thesameoccurswiththephones.Sohere,weusetheIDgiventoretrievethesedataandtheshowittothescreen.

Finally,we’llgotothesearchfunctionbutthistimewewillsearchbythenameofthecontactwewanttofind.Thecodeforthisfunctionlookslikethis:voidSearchByName()

{

boolfound=false;

stringname;

cout<<"\n\nEnterthenametosearch:";cin>>name;

for(inti=0;i!=Names.size();i++){

if(Names[i]==name)

{

{

cout<<"Name:"<<Names[i]<<"\n";cout<<"Phone:"<<Phones[i]<<"\n";found=true;

}

}

if(!found)

{

}

}

Herewedeclaredtwovariables,foundandname.NamewillbethestringthatwewanttolookforandfoundisavariableofdatatypeBOOL(thosethatareonlytrueorfalse)andwilltellusifoursearchwaseithersuccessfulorfailed.

First,werequesttheusertoenterthenametosearchforandafterthis,wewilluseaforlooptocyclethroughalloftheelements.Theaccumulatorisstarted,likeusual,atzero.Now,noticehowourconditionhaschanged:I!=Names.size()

Thankstothislittlefunctionnamedsize(),ourforloopwillbeabletogothroughalltheelementsuntilitreachestheendofitself.Withthissize()function,wecanbecompletelysurethatwedonotgooutofboundofourvector.Ifyoudonotusesize(),thenyouwillhavesomekindofriskloopingthroughthevector.Ifthiserrorhappens,itwillbeonruntimeandthecompilerwontwarnyouaboutthis,soit’ssafertousethesizefunction.

EachlapthatourloophaswillcomparethestringattheIpositioninthevectorwiththestringthattheuserentered.Ifbothstringsareequal,thenitwillshowtheuserthenameandthephoneforthatcontact.Also,itwillchangethestateoffoundtotrue.

Afterexitingtheloop,itwillcheckifthevariablefoundisfalse.Theexclamationsignatthestartofthevariablemeansanegation(NOT)so,iffoundISfalse,thentheflowwillfallontotheblockofcodeoftheifandshowtheuserthemessage“Nocontactwasfoundwiththisname”.

Afterverifyingthestate,thefunctionendsandtheflowoftheprogramreturnstothemainfunction.

cout<<"Nocontactwasfoundwiththisname!\n\n";

CHAPTER5:PROJECT#3SCHOOLNOTESSYSTEM

Thisprojectwillhavecontrolofstudentinformationalongwiththeirnotesstoredintoafileontheharddrive.Also,theprogramwillbeabletocapturethenotesandtogenerateeachstudent’sbulletinandwriteittoanoutputfile(inaplaintextformat).Thefirstthingforstartwillbedefiningtheheaders:#include<fstream>

#include<iostream>

#include<string>

#include<vector>

usingnamespacestd;

Thenewheaderthatyoucannoteis<fstream>.Itstandsfor“filestream”anditcontainsallofthefunctionsandobjectsweneedtomanipulatefilesfromtheoperatingsystem.Thereststaysthesame.Nowlet’sdefinethemainfunction:intmain()

{

intsel=0;

while(true)

{

cout<<"SchoolControl\n\n";cout<<"[1]Addstudent\n";cout<<"[2]Addnotes\n";cout<<"[3]Searchstudent\n";cout<<"[4]Readkardex\n";cout<<"[5]Printkardex\n";cout<<"[6]Exit\n";

cout<<"Choice>";

cin>>sel;

switch(sel)

{

case1:

AddStudent();

break;

case2:

AddNote();

break;

case3:

SearchStudent();

break;

case4:

ReadKardex();

break;

case5:

PrintKardex();

break;

case6:

return0;

break;

default:

break;

}

}

return0;

}

Thisfunctionstaysalmostidenticaltotheoneinourproject1.Wedefinethemenuforthedifferentoptionsandlettheuserdecidewhichpartoftheprogramwantstofollow.Wedefinefunctionsforaddastudent,addnotes,searchforastudent,readkardexandprintkardextoatxtfile.Now,thedefinitionfortheaddStudentpart:voidAddStudent()

{

//Temporalvariable

stringtemp;

//Vectorforholdingallvariablesvector<string>Data;

//[0]FirstName

//[1]LastName

//[2]Phone

//[3]IDnumber

cout<<"Enterstudentfirstname:";cin>>temp;

Data.push_back(temp);

cout<<"Enterlastname:";cin>>temp;

Data.push_back(temp);

cout<<"Enterphonenumber:";cin>>temp;

Data.push_back(temp);

cout<<"Enterstudentnumber:";cin>>temp;

Data.push_back(temp);

//OpenthefileusingtheIDnumberstringfileName;

fileName=Data[3]+".dat";

ofstreamfile;

file.open(fileName.c_str());

//Writethedata

file<<Data[0]<<endl;file<<Data[1]<<endl;file<<Data[2]<<endl;file<<Data[3]<<endl;file.close();

}

Inthisfunction,wedefinetempasthevariableforinputandavectornamedDatawhichwillcontainallofthedataforthenewstudent.Inthecomments,youcanseetheindexwhereeachdataisstored.Afterthis,weuseinputandoutputinstructionstomaketheuserenterthedatafromthestudentandsaveittothevector.

Whenwearefinished,wecreateanewstringnamedmakeFile.Thisstringwillhavethefilenameforthefilewewanttocreate.Inthiscase,itwillbethestudentnumber(storedinData[3])plusthe“.dat”extension.

Theofstreamobject(standingforoutputfilestream)allowsustoopenafileforwritingmode.Weopenthefileusingtheopenfunctionandinsidethecurlybracesthefilename.Thec_str()functionconvertsourstringtoaC-string.

Likethecout<<object,theofstream<<alsosendsoutputinformation,butinthiscasedoesnotgotothedisplay,buttoouroutputfile.Remember!<<operatorsmeanOUTPUTinanystream(iostream,fstream,sstream,estc).

Andfinallyweclosethefile.

voidAddNote()

{

vector<string>Subject;

vector<string>Note;

stringtemp;

stringstudent;

intz=0;

cout<<"EnterthestudentIDtoaddnotes:";cin>>student;

while(true)

{

cout<<"\nEntersubject:";cin>>temp;

Subject.push_back(temp);

cout<<"Enternote:";

cin>>temp;

Note.push_back(temp);

cout<<"Doyouwanttocontinue?[0]Yes[1]No>";cin>>z;

if(z!=0)

{

break;

}

}

stringfileName;

fileName=student+".cal";

ofstreamfile;

file.open(fileName.c_str());

for(inti=0;i!=Subject.size();i++){

}

file.close();

}

TheAddNotefunctionwillcapturethesubjectnamesanditsnotesforanystudent.Wedefinetwovectors,oneforthenamesandtheotheroneforthenotesandaZvariablewhichwillallowtheusertoenterasmanysubjectsashewants.First,thefunctionasksforthestudentIDandafterthat,insideaendlessloop,theuserisrequestedtoenterthesubjectandthenoteforthatsubject.

Afterthis,theprogramaskstheuserforcontinueenteringnotesorexit.

Whenallthesubjectsareentered,wecreateanewfilewiththestudentIDplusthe“.cal”extension.Weopenthefileandwriteinsideofiteachsubjectanditsnote.

Noticehowweloopthroughthevectorandsendtothefilethesubjectandnoteineachpositionandjumpalineattheend.Whenwefinish,thefilemustbeclosed.

voidSearchStudent()

{

stringnumber;

cout<<"InsertstudentID:";cin>>number;

stringfileName;

fileName=number+".dat";

ifstreamfile;

file.open(fileName.c_str());

vector<string>data;

if(file.is_open())

{

file<<Subject[i]<<""<<Note[i]<<endl;stringin;

while(!file.eof())

{

file>>in;

data.push_back(in);

}

cout<<"Firstname:"<<data[0]<<endl;cout<<"Lastname:"<<data[1]<<endl;cout<<"Phone:"<<data[2]<<endl;cout<<"Studentnumber:"<<data[3]<<endl;file.close();

}

else

{

}

}

ThetaskfortheSearchStudentfunctionistolookforadeterminedfilewiththestoreddatafromastudent.Wefirst,requesttheusertoentertheIDandthisIDisconcatenatedtothe".dat”extension.Here,weusetheifstreamobject(inputfilestream).Theifstreamobjectcontainsafunctionnamedis_openthatindicatesusifanyfilehasbeenopenedcorrectly.

Ifthisisthecase,thenwemustreadthefile.Weusethestringintostorethestringsfromthefile.

Thefunctioneof()standsfor“endoffile”andallowustoloopthroughthefileuntilitreachestheend.Westoreallthelinesinsidethedatavectorandafterthereadingisfinished,wesendtothedisplaythedata.

Whenwefinish,thefilemustbeclosed.Ifthefilecouldnotbeopened,theprogramwillshowthemessage“Studentnotfound”tothedisplay.Nowlet’sgototheReadKardex()function:voidReadKardex()

{

stringnumber;

cout<<"InsertstudentID:";cin>>number;

stringfileName;

fileName=number+".cal";

ifstreamfile;

file.open(fileName.c_str());

vector<string>data;

if(file.is_open())

{

cout<<"Studentnotfound\n";stringin;

while(!file.eof())

{

file>>in;

data.push_back(in);

}

file.close();

for(inti=0;i!=(data.size()/2);i+=2){

cout<<data[i]<<"\t"<<data[i+1]<<endl;}

}

else

{

}

}

Asallofthisprogram’sfunctions,requestforthestudentIDandconcatenatesitthe“.dat”extension.Then,triestoopenthisfile.Ifitisopened,thenwecapturewordbywordandaddittothedatavector.Whenitfinished,thefileisclosed.Now,thefollowingforloopmaylookverybizarreforyou.Istartsatzero.TheconditionforthiswillbeIdifferentthanthesizeofthevectordividiedbytwoandthenIwillincrementbytwotimes.Thisloopiswrittenthiswayforallowingustoreadthedatafromthevectorinpairs,asyoucanseeonthecoutline.TherewereadData[i]andData[i+1].

voidPrintKardex()

{

stringnumber;

cout<<"InsertstudentID:";cin>>number;

vector<string>data;

vector<string>notes;

stringfileName1,fileName2;

fileName1=number+".dat";

fileName2=number+".cal";

ifstreamdataFile,noteFile;

dataFile.open(fileName1.c_str());noteFile.open(fileName2.c_str());stringtemp;

if(dataFile.is_open())

{

cout<<"Studentorkardexnotfound\n";while(!dataFile.eof())

{

dataFile>>temp;

data.push_back(temp);

}

}

else

{

cout<<"Studentnotfound\n";return;

}

if(noteFile.is_open())

{

while(!noteFile.eof())

{

noteFile>>temp;

notes.push_back(temp);

cout<<"\n\nREAD:"<<temp<<endl;}

}

else

{

{

cout<<"Kardexnotfound\n";dataFile.close();

}

dataFile.close();

noteFile.close();

//Beginswritingthekardex

ofstreamkardex;

stringfileName3;

fileName3="Kardex"+number+".txt";kardex.open(fileName3.c_str());//Writetitles

kardex<<"STUDENTKARDEX\n\n";kardex<<"NAME:"<<data[1]<<","<<data[0]<<endl;kardex<<"PHONE:"<<data[2]<<endl;kardex<<"NOSTUDENT:"<<data[3]<<endl<<endl;kardex<<"NOTES"<<endl;kardex<<"-------------------------------"<<endl;for(inti=0;i<=(notes.size()/2);i+=2){

}

kardex.close();

cout<<"Kardexgenerated\n\n";}

Finally,thePrintKardex()functionisbasicallyacombinationfromtheSearchStudent()andtheReadKardex().Furthermore,itgeneratesafilenamed“Kardex”+numberID+“.txt”.Insidethisfile,therewillbeareportfromthestudent’sdataanditsnotes.

kardex<<notes[0]<<"\t"<<notes[1]<<endl;

CHAPTER6:PROJECT#4SALESPOINT

Thisprojectwillhaveacatalogofdifferentproduct thataresoldinacommonsupermarket.Alltheproductsarestoredinafileincludingtheirprice.Thisfilecanbemodified.Theprogramgivestheoptiontotheuserforsellingproductstothecustomers, calculating the subtotal, the taxand the final totalof thewholesale.When the sale is finished, the itemquantity and the total are storedon aseparate file. This file stores all the sales and will be used to generate totalreports from the sales. Let’s start as always, with the libraries: #include<cstdlib>

#include<fstream>

#include<iostream>

#include<string>

#include<vector>

usingnamespacestd;

vector<string>products;

vector<float>prices;

These are all known libraries except for<cstdlib>.This is aC library andwe

willuse thefunctionatof,whichwillconvertastringtoafloatvalue.Wewillseethisalittlebitlater.Thetwoglobalvectorswillholdthenameandthevalues(prices)foreachitem.Let’sgotothemainfunction,whichisverysimilartothepreviousprojects:intmain()

{

LoadValues();

intsel=0;

while(true)

{

cout<<"SUPERMARKETSYSTEM\n\n";cout<<"[1]Newclient\n";cout<<"[2]ViewCatalog\n";cout<<"[3]Viewsales\n";cout<<"[4]Exit\n";

cout<<"Select>";

cin>>sel;

switch(sel)

{

case1:

NewClient();

break;

case2:

DisplayCatalog();

break;

case3:

DisplaySales();

break;

case4:

return0;

break;

}

}

return0;

}

Beforeanything,youcanseethatthefirstthingwedoiscalltotheCallValuesfunction.Thisfunctionwillloadthevaluesoftheproductsfromthefilenamed“products.dat”.Lookatthefunction:voidLoadValues()

{

//Theprogramwillloadafilenamed"products.dat"

//Thisinformationwillbestoredtothevectorsstringtemp;

floattval=0.0;

ifstreamproductInfo;

productInfo.open("products.dat");if(productInfo.is_open())

{

while(productInfo>>temp){

products.push_back(temp);

productInfo>>temp;

tval=atof(temp.c_str());

prices.push_back(tval);

}

}

else

{

loaded.\n";

}

}

Theprogramopensthefile“products.dat”andifit’sopen,thenwillreadallthevalues.Thefirstoneisinsertedinproductsandthen,readsagain, thistimeforthe price. The price is read as a cout << "Product information file not found.Data was not return; string, but we cannot make arithmetic operations withstrings, soweuseatof() toconvert fromstring to float.Thisvalue isstored intvalandweinserttvalinthepricesvector.

Returning tomain,wehaveour typicalmenuand theuser isallowed toselectwhich option wants to execute. The first option, NewClient(), will perform anewsale:voidNewClient()

{

intid=0;

intqty=0;

intitemqty=0;

floatsum=0.0;

cout<<"NEWSALE\n";

cout<<"INSTRUCTIONS:\n";cout<<"EntertheIDoftheproduct.Afterthis,enterthequantityandpressenter\n";

cout<<"Ifyouhavefinished,enter-1onproductandwillexit\n\n";

while(true)

{

cout<<"EnterproductID:";cin>>id;

if(id==-1)

{

break;

}

cout<<"Enterquantity:";cin>>qty;

floatvalue=prices[id]*qty;sum=sum+value;

itemqty++;

cout<<endl;

}

floattax=(sum*0.0825);

float total = (sum+(sum*0.0825)); // After the customer has entered all itemscout<<"\nYouhavebought"<<itemqty<<"items\n";cout<<"Subtotal:"<<sum<<endl;cout<<"Tax:"<<tax<<endl;cout<<"Total:"<<total<<endl;floatmoney=0.0;

while(true)

{

menu\n\n";

cout<<"Money:";

cin>>money;

if(money>=sum)

{

cout << "Your change is " << (money-sum) << endl; cout << "Thanks forshopping.Returningtomainbreak;

}

cout<<"Notenoughmoney.Re-entermoney\n";}

//Writethesaletothesalesfileofstreamsales;

//Inofstream,ios::appisaflagthatindicatesthatthedatawritten

//totheoutputwillbeappendedattheendofthefile.

sales.open("sales.dat",ios::app);if(sales.is_open())

{

sales<<itemqty<<"\t"<<total<<endl;sales.close();

}

else

{

}

}

Thefirstthingistodelareourcountervariables.Idwillhavetheidforenteringitems.Theqtywillstorethenumberofthesameitemsboughtbythecustomer.Itemqtywillholdthetotalitemsboughtbythecustomerandsumwillhavethesumofallthepricesoftheproducts.Insideourendlessloop,werequesttheuserto enter the ID for the product. If we do not want to enter a new item andproceedtocheckout,wemustenter-1.Anythingelsewilllookforaitem.Whenaitemisinserted,theusermustenterthequantityofthesameitem.Wecalculatetheitemtotalwiththeproductofthevalueoftheitemandthequantity.

Thisloopwillcontinueforalltheitemsthecustomerwants.Whenheexitswiththe -1, then theprogramgoes to thecheckout.Calculates the taxand the totalanddisplaysthesevaluestothescreen.Theprogramthen,requeststhecustomertoenteraquantityofmoneytopay.Ifheentersavaluethatislowertothetotal,thenitwillnotproceed.Whentheuserentersavalidvalue,thencalculatesthechangeandopens the“sales.dat”file.Note the ios::app.This indicates that thefilewillnotbeoverwritten.Thisvaluewillbeaddedattheendofthefile.Wewillsavetheitemquantityandthetotalofthesaleandfinally,closethefile.

Now,wewilllookattheDisplayCatalog()function.Thisfunctionwillshowthecustomer all the products with their respective price: cout << "SALES FILENOTFOUND!NODATASAVED\n";voidDisplayCatalog()

{

cout<<"Productcatalog\n\n";cout<<"ID\tPRODUCT\tPRICE\n";cout<<"-----------------------------------\n";for(inti=0;i!=products.size();i++){

prices[i]<<endl;

}

cout<<"\n\n";

}

Thisoneisverysimple.Itloopsbothvectorsandshowsonthescreenthevaluesof both vectors at the same position. The last function isDisplaySales(). Thisfunctionwillreadoursalesfileanddisplayareportfromthetotalofsales:voidDisplaySales()

{

cout<<"SUPERMARTKETSALES\n\n";cout<<"Stats\n";

stringtemp;

intsalesCount=0;

intitemCount=0;

floatsumCount=0;

floattval=0.0;

ifstreamsalesFile;

salesFile.open("sales.dat");

if(salesFile.is_open())

{

cout<<"["<<i<<"]\t"<<products[i]<<"\t\t"<<while(salesFile>>temp)

{

salesCount++;

tval=atof(temp.c_str());

itemCount+=tval;

salesFile>>temp;

tval=atof(temp.c_str());

sumCount+=tval;

}

salesFile.close();

}

else

{

cout<<"SALESFILENOTFOUND!Datacannotbegenerated\n\n";return;

}

cout<<"Totalofsales:"<<salesCount<<endl;cout<<"Totalofitemssold:"<<itemCount<<endl;cout<<"Totalearnings:"<<sumCount<<endl;cout<<"\n\n";

}

Wewillinitializeourcountersatzero.Salescountwillholdthenumberofsales.Itemcountthetotalofitems.Sumcountthetotalofmoneysalesandtvalwillbeourtemporalvalueforreading.

Weopenthefile“sales.dat” andwewillreadeverything.First,readtheitemsandconvertittofloatandincrementsalescoundbyoneandalsoitemCountbytval.Afterthis,wereadthenextword,whichisthemoneyofthesale.ThevalueisconvertedtofloatandaddedtosumCount.

Whentheloopends,thefileisclosed.

Finally,weshowtotheoutputthetotalofthisreport.

CHAPTER7:PROJECT#5SIMPLECOMMANDLINEENCRYPTIONSYSTEM

Thisprojectisasimpleencryptionanddecryptionsystem.Encryptionistheprocessofhidinginformationfromplaintextfromtheuser.Thinkalittlebitaboutthefilesthatwehaveusedintheotherprojects.Allofthemareplaintext.Youcanopenthesefilesusingnotepadandyoucanseeallthecontentwithoutanyproblem.Forthestudyingpurpose,thereisnoproblem.However,inrealsystems,theinformationmustbeprotectedandhiddenfromtheuser.Thatistheobjectiveofthisproject.Storinginformationinadifferentwayandafterthis,readingandrestoretherealinfo.Let’slookattheinitialdirectives://Programthatwillencryptanygivenfile//ThisprogramusestheMaptemplateandusescommandlineinput#include<iostream>#include<fstream>#include<cstring>#include<string>#include<map>#include<vector>usingnamespacestd;Therearetwonewlibraries:<cstring>and<map>.ThecstringlibraryisanoriginalClibrarythatwewilluseforstringcomparison.Ithasmanymorefunctionalitiesforstrings,butforthiscase,wewillbelimitedtoonlythatfunction.

Thenextone,map,isaSTLcontainer.Forexplainingthis,lookatthevector.Itholdsmultiplevaluesusingasinglevariablename.Allofthesevaluesaredifferentfromthembytheindex,thatnumberthatweputinsidebrackets.So,what’supwithmap?Well,mapisacontainerwheretheindexisnotanumber.Inmap,whatwestoreissomethingnamedpair.Itconsistoftwointernalvalues:keyandvalue(incode:firstandsecond).Thinkaboutthislikeadictionary.Inthedictionaryyoudonotlookforawordusinganumber.Youlookforadefinitionbyaword,andthatiswhatwedowithmap.map<string,string>theKey;map<string,string>revKey;vector<string>keys;vector<string>values;Thefirstthingwedeclareisourmap.Nowinsidethesymbolsisstring,string.Thismeansthatbothkeyandvaluewillbestrings.Ourothertwovectorswillholdindependentlythekeysandvalues.Revkeywillbethekeyforthedecryptionprocess.Now,herecomesthemostinterestingpart:loadingourvaluesandpopulatingthemap!voidLoadMap()

{

//Mappingtherealvaluevstheencryptedvaluekeys.push_back("a");values.push_back("0");keys.push_back("b");values.push_back("d");keys.push_back("c");values.push_back("b");keys.push_back("d");

values.push_back("x");keys.push_back("e");values.push_back("g");keys.push_back("f");values.push_back("i");keys.push_back("g");values.push_back("z");keys.push_back("h");values.push_back("u");keys.push_back("i");values.push_back("a");keys.push_back("j");values.push_back("c");keys.push_back("k");values.push_back("y");keys.push_back("l");values.push_back("3");keys.push_back("m");values.push_back("q");keys.push_back("n");values.push_back("7");keys.push_back("o");values.push_back("f");keys.push_back("p");values.push_back("p");keys.push_back("q");values.push_back("v");keys.push_back("r");values.push_back("8");keys.push_back("s");values.push_back("e");keys.push_back("t");values.push_back("j");keys.push_back("u");values.push_back("5");keys.push_back("v");values.push_back("h");keys.push_back("w");values.push_back("r");keys.push_back("x");values.push_back("2");keys.push_back("y");values.push_back("m");keys.push_back("z");values.push_back("n");keys.push_back("");values.push_back("");for(inti=0;i!=keys.size();i++){pair<string,string>a;a.first=keys[i];a.second=values[i];theKey.insert(a);a.first=values[i];a.second=keys[i];revKey.insert(a);

}

}

Thiscodeisalittlebittedious.Hereitisthekeyofourencryption.Thefirstrow,usedforkeys,willbeouroriginalvalues.Thesecondrowwillbeourencryptedvalues.Thatmeans,everyletter‘a’willbechangedfora‘0’.Everyletter‘t’willbechangedfora‘j’andsoonwiththerestoftheletters.InthiscodeIdidnotinsertedcapitalletters.So,ourmessagecanonlycontainsmalllettersandspaces.Everythingelsewillnotbeencrypted.Butasyoucansee,itisveryeasytoentermorevaluesinsidethevector.Then,wehaveourloop.Itwillgofromzerotothesizeofourkeys.Inside,wedeclareanewPAIRofvalues,bothoftypestring.Thepairnameis‘a’.Thevalueforfirst(thekey)willbeourkeystringatpositionIandthevalueforoursecond(theactualvalue)willbeinsidetheIpositionofvalues.Afterwecreateourpair,itwillbeinsertedintothemapusingtheinsert()function.Thesamegoesforthedecryptionkeyinrevkey,butherethevaluesareinverse.Now,themainfunctionwillbedifferentthanbefore.Takeaverycloselooktothefollowingpieceofcode:intmain(intargc,char*argv[])

{

//argc-numberofparametersenteredthroughcommandline//argv-parameterenteredfromcommandline//argv[1]-filetoprocess//argv[2]-//-eEncryption//-dDecryptioncout<<"Loadingdata.\n";LoadMap();vector<string>inputData;

stringmessage;stringmessageEnc;stringoutputPath;if(!strcmp(argv[2],"-e"))

{

}

elseif(!strcmp(argv[2],"-d"))

{

}

outputPath+=argv[1];ifstreaminputFile;ofstreamoutputFile;cout<<"Openingfiles.\n";inputFile.open(argv[1]);outputFile.open(outputPath.c_str());if(inputFile.is_open())

{

{

outputPath="ENCRYPTED";outputPath="DECRYPTED";//Obtaintheinputcout<<"Readingfiles.\n";inputFile>>message;//Foreachletterintheinput,generateits//correspondingencryptedvaluefor(inti=0;i!=message.size();i++){cout<<"Encrypting.\n";stringtempChar;tempChar=message.at(i);//Differentiatebetweenencryptinganddecryptingif(!strcmp(argv[2],"-e"))

{

}

elseif(!strcmp(argv[2],"-d"))

{

}

}

else

{

}

}

//Generatetheoutputcout<<"Writingencryptedfile.\n";outputFile<<messageEnc;inputFile.close();outputFile.close();messageEnc+=theKey[tempChar];messageEnc+=revKey[tempChar];

}

else

{

}

cout<<"Processfinished.Outputfileis"<<outputPath<<".\n";cin.get();return0;

}

Whatintheworldisargcandargv?Well,youmayhaveheardaboutcommandline.Inthecommandlineyoucanexecuteprogramsinaverfastinterfaceandhavetheoptiontoconfiguretheseprograms.Thisparticularprogramisdesignedonlytoworkincommandline.AnargumentisavaluethatispassesthroughthecommandlineanditgoesinsideourC++program.Thevariableargcisthecountofargumentsthatourprogramhasreceived.Bydefault,isalwaysone:theprogramname.Thesecondparameter,argv,hastheactualvaluesthattheuserenterstotheprogram.Thisprogramwillreceivetwoarguments:

Thefiletoencrypt/decrypt

Themodeforprocessingcout<<"File"<<argv[1]<<"notfound.\n";Inthefolderwhereyouhaveyourexe,createanewfilenamed“data.txt”andwritesomething,forexample“hello”andsaveit.Afterthis,gotothesettingsofyourprojectandlookforsomethingcalled“ExecutabletoRun/Debug”.After“./$(ProjectName)”enter:data.txt–eTheserepresentthefileyouwanttoencryptand–emeansthatitwillperformanencryption.Thisoptionallowsthecompilertoautomaticallyinsertparametertoyourprogramwithouthavingtogoallthroughcommandline.Butnowlet’sreturntothecode.WeloadourmapsusingLoadMap()functionandavectornamedinputdata.Thisonewillhaveallthestuffthatisinsidethefile.Messagewillhavethetotalmessage.MessageEncwillhavethetransformedmessage.OutputPathwillhavethenameofthefilewheretheencrypted/decryptedmessagewillbewritten.

Afterthis,wewillsianifstructure.Strcmpisastringcomparison.Ifthesecondargument(argv[2])is“-e”thenitmeansthatisisanencryption.So,thefilenamewillhavethe“ENCRYPTED”label.Ifithasthe“-d”string,thenitwillbeadecryption.Then,weproceedtothefileprocessing.Herewewillbeusingbothinputandoutputfilestreams.Theinputhasouroriginalmessageandtheoutputthetransformedmessage.Weopentheinputandreadallthemessage.Afterthis,wewilltreatourstringlikeifitwasavector.Foreachcharacterinsidethestring,willfinditscounterpartonthemapsforitstranslation.However,the[]operatorarenotallowedinastring.Inordertoperformanindexlecture,wemustusetheat()function.TheactualcharacterwillbestoredintothetempCharvariable.Whenwehavethischaracter,werunagainthecomparison.Ifthesecondargumentis“-e”itmeansthatitisanencryption.So,weencrypt.WewillappendattheendofthemessageEnctheVALUEcorrespondingtoitsKEY.So,theKEYwillbetheletterandthevaluewillbethevalueassociatedwiththatkey.AllfromthetheKeymap.Ifitisadecryptionprocess,then,insteadofcomparingwiththeKey,wewillcompareittotherevKeymap.Whenitfinisheswithallthecharacters,amessageappearsinoutconsoleandwritestoouroutputfiletheprocessedmessage.Finally,bothfilesareclosed.Iftheinputfileisnotfound,thenitwillshowanerrormessage.Theprogramdoesnotshowanymessage.Everythinggoestothefiles.Finallywefinishtheprogramandreturnthemainfunction.

CHAPTER8:PROJECT#6DUELGAME

Thisprojectisasimpledemonstrationofanautomatedvideogame,everythingrunningthroughconsole.Themainideaisaduel.Aconfrontationfromcowboyvscowboy.Therearethreedifferentkindsofcowboys:

Basic

Resistence

FastAttack

WheretheBasichasnormalvalues,theresistancehaslowerattackpointbutmorelifepointsandthefastattackhasmoreattackpointsbutlesslifepoints.Theuserwillenterthekindofcowboythathewants.Afterthis,themachinewillrandomlyselectanyofthethree.Inthisprogram,wewilluseclassesfordefiningourtypesofcowboys.Let’slookattheheaders:#include<iostream>

#include<cstdlib>

#include<ctime>

usingnamespacestd;

Thenewheaderinthisprojectis<ctime>.CtimeisanoriginalCheaderandwillbeusedtogeneraterandomnumbers.Now,let’sseeourclasses:c lasscowboy{

public:

intlife;

intplayer;

intmaxatk;

intminatk;

inttype;

cowboy()

{

}

cowboy(intv,intam,intan,intt){

life=v;

maxatk=am;

minatk=an;

type=t;

}

};

ThecowboyclassisourdefinitionforCowboy.Asyoucannotice,itcontainsitsfundamentalvalues:lifepoints,theplayer,themaximumattackpoints,theminimumattackpointsandthetypeofcowboy.

Itsconstructor,cowboy(int,int,int,int)isafunctionthatwillletusassignthefourvaluesinasingleinstructionwhenthecowboyiscreated.BeforegoingintoourDuelclass,let’slookthemainfunction:intmain()

{

dueltheDuel;

theDuel.mainmenu();

system("pause");

return0;

}

Inourmainfunction,weonlydefineaninstanceofourDuelclassandwestarttheduelwiththemainmenufunctionfromDuel.Here,theflowcontrolisinsidetheduel,andnotmain.

classduel

{

public:

duel()

{

}

voidmainmenu()

{

intchoice;

do

{

cout<<"MainMenu\n\n";cout<<"1-Play\n";

cout<<"2-History\n";cout<<"3-Exit\n\n";cout<<"Select:";

cin>>choice;

if(choice==1)

{

}

elseif(choice==2)

{

}

}

while(choice!=3);

}

UpuntilherewedefinetheMainMenuoftheduelasifwewereonthemainmenuonotherprojects.Thisisanotherwayofworkingaroundwithmenus.

voidselectcowboy()

{

cout<<"\n\nSelectyourcowboy:\n\n";cout<<"1-Basic\n";

cout<<"2-Resistence\n";cout<<"3-FastCowboy\n\n";cout<<"Choose:";

intchoice;

cin>>choice;

cowboyplayer;

cowboymachine;

if(choice==1)

{

player.life=30;

player.maxatk=15;

player.minatk=8;

player.player=1;

player.type=1;

}

elseif(choice==2)

{

player.life=50;

player.maxatk=15;

player.minatk=8;

player.player=1;

player.type=2;

}

elseif(choice==3)

{

player.life=28;

player.maxatk=9;

player.minatk=5;

player.player=1;

player.type=3;

}

intrival=rand()%3+1;

if(rival==1)

{

machine.life=30;

machine.maxatk=15;

machine.minatk=8;

machine.player=1;

machine.type=1;

}

elseif(rival==2)

<<machine.life<<"\n\n";{

machine.life=50;

machine.maxatk=15;

machine.minatk=8;

machine.player=1;

machine.type=2;

}

elseif(rival==3)

{

machine.life=28;

machine.maxatk=9;

machine.minatk=5;

machine.player=1;

machine.type=3;

}

else

{

cout<<"Error.Choice="<<choice<<"\n";}

//Iniciaelduelo

cout<<"\n\nPreparingduel\n\n";cout<<"Playerlife:"<<player.life<<"\nMachinelife:"

cout<<"Duelstartsnow!\n\n";bools=true;

while(true)

{

if(s==true)

{

player.minatk)+player.minatk;points\n";

}

else

{

machine.minatk)+machine.minatk;points\n";

"\n";

"\n";

}

cout<<"Player'sremaininglife:"<<player.life<<cout<<"Machine'sremaininglife:"<<machine.life<<if(player.life<=0)

{

}

elseif(machine.life<=0){

}

if(s==true)

{

}

else

{

}

}

}

voidstory()

{

}

};

Let’sexplainthecodeinsideSelectCowboy().Yes,itisverylong,butlet’slookatitveryclosely.

Thefirstthingisthatwerequesttotheplayertoselectwhatkindofcowboydoeshewant.Basic,resistanceorFast.

Afterthis,wecreatetwocowboys,onefortheplayerandanotheroneforthemachine.Thencomesanifinstruction.Iftheuserselectthebasiccowbow,youcanseetheparameterthatwillhavethecowbow.Thesevaluesaretheonesthatchangeineachtypeofcowboy.

Afterthis,wedefinethetypeofcowboythatourrivalwillhaveusingtherand()function.Thisfunctionisincludedinthectimeheader.Thesameconfigurationparametersareappliedforthecowboythatthemachinewilluseintheduel.

Whenwefinishconfiguringthisparameters,finally,theduelstarts.Thesvariable,whichisaboolvariable,willindicateustheturn.Ifsistrue,thentheturnisfortheplayer.Ifthesisfalse,thenit’sthemachine’sturn.

Enteringtheplayer’sturncode,theattackthattheplayerwillhavewillbearandomnumberbetweenitsmaxattackanditsminattack.Duetotheconfigurationoptions,iftheplayerhasthefastattackoption,thentheattackwillbedoubled.However,ifthemachinehastheresistencetype,theattackwillbe

dividedbythree.

Afterthis,thepromptwillshowwithhowmanypointstheattackwasmadeandtheseattackpointswillbesubstractedfromthemachine’slifepoint.Thissameprocesshappenswhenit’sturnforthemachinetoattack.Inthiscase,theplayer’slifepointsaredecreasedinrelationshipwiththemachine’sattackpoints.

Afterbothplayersattack,weshowonthescreentheremaininglifepointsforeachplayerandthenevalueatewetherbothplayersarestillalive.Ifanyofthetwohaszeroornegativelifepoints,thegameendsandshowsamessagewheretheplayerlostorwon.Ifnoneofthishappens,thenthevalueof‘s’willbeinvertedandtheloopwillstaralloveruntilaplayerlosesalloftheirlifepoints.

Finally,thestoryfunctionisonlyanadd-onforthegame.Youcanreplacethesestringwithanythingthatyouwish.

cout<<"Hereyoucaninsertanyhistory\n";cout<<"Fillthispart\n";

CHAPTER9:PROJECT#7POKERGAME

Inthisfinalproject,wewillsimulateafullOOPPokerGame.Here,wewillusemultipleclasses.So,let’sgetstarted.Firstofeverything,wemustdefineourclassforanycard.Herewewillworkwithmultiplefiles,so,createanewfilenamedcard.handaddthiscode:#ifndefCARDH_#defineCARDH_classCard

{

public:intnumber;intsign;voidAssign(int,int);

};

#endifWhenweusemultiplefiles,the#ifndefisapre-processordefinition.Withthis,weassurethatthisfilewillonlybeincludedonce.Ifitisincludedmultipletimesinthesameprogram,willcausetroubleforduplicatedsymbols.So,ourcardwillhaveitsnumber,itssignandafunctionnamedAssign,and

withthisfunction,wewillassigneachcarditsvalues.Now,createanewfilenamed“card.cpp”:#include"card.h"voidCard::Assign(intnum,intsi){number=num;sign=si;

}

Inthisfile,therewillbetheimplementationsofourfunctions.Here,weassigntheparametersfromthefunctiontothevaluesthattheobjectwillhave.Noticethatwemustincludeour“card.h”file.Thatistheonethatwecreatedbefore.Itmustbeincludedsoitcanimplementthefunctions.Nowthatwehavethecardclasss,wemustcreatetheplayerclass.Player.hdefineslike:#ifndefPLAYERH_#definePLAYERH_#include<iostream>#include<string>#include<vector>#include"card.h"usingnamespacestd;classPlayer

{

public:stringname;vector<Card>hand;voidGetCard(Card);voidShowHand();

};

#endifThePlayerclasswillhavetwoproperties:thenameoftheplayerandavector.Look:herewedonotuseanystring.ItisaCARD!Theclasswedefinedpreviously.Thisvectorofcardscanbeviewedlikethehandthattheplayerowns.Also,wehaveafunctionnamedGetCard(),thisfunctionwillallowourplayertoreceivecardsandaddthemtoitshand.Andfinally,thefunctionShowHand().Thiswillonlyshowthevaluesinsidethehand.Let’sseetheimplementationthatwillbeinside“Player.cpp”:#include<vector>#include"card.h"#include"player.h"usingnamespacestd;voidPlayer::GetCard(Cardc)

{

hand.push_back(c);

}

voidPlayer::ShowHand()

{

cout<<name<<"'shand:";for(inti=0;i!=hand.size();i++){cout<<hand[i].sign<<"-"<<hand[i].number<<"";}cout<<endl;

}

Inthisimplementation,wemustincludeCardandPlayerbecausewewillbeusingboth.ThefunctionCardreceivesaparameteroftypeCardandisinsertedinthehand.Theshowhandloopsthroughthehandoftheplayer,obtainsthevaluesforeachcardanddisplaysthemtothescreen.But…whowillgivethecards?Thedealerobviously!Let’sdefineaclassforourdealerin“dealer.h”:#ifndefDEALERH_#defineDEALERH_#include<string>#include<vector>#include"card.h"

usingnamespacestd;classDealer

{

public:vector<Card>Deck;Dealer();CardGiveCard();voidShuffleCards();

};

#endifThedealeronlyhasonepropertybutitisthemostimportantpropertyfromthegame:Thedeck!Andhowwillwerepresentdedeck?Alsoasanvectorofcards.Thedealerwillalsohavethehabilitytogivecardsandtoshufflethecards.Now,letslooktheimplementation:#include<algorithm>#include<vector>#include<string>#include<random>#include<chrono>

#include"dealer.h"#include"card.h"usingnamespacestd;CardDealer::GiveCard()

{

Cardc=Deck[0];Deck.erase(Deck.begin());returnc;

}

voidDealer::ShuffleCards()

{

unsignedseed=std::chrono::system_clock::now().time_since_epoch().count();shuffle(Deck.begin(),Deck.end(),std::default_random_engine(seed));}Dealer::Dealer()

{

for(inti=0;i!=12;i++){for(intj=0;j!=4;j++)

{

CardnewCard;newCard.number=(i+1);newCard.sign=(j+1);Deck.push_back(newCard);

}

}

}

Hereweinsertednewlibraries:

Algorithm:willbeusedtoshuffleourdeck

Random:generatearandomnumber

Chrono:accesstotiminglibrariesFirst,lookattheGiveCard().Itwillselectthecardthatisonthetopofthedeck.Willremoveitformthemandthenextractittoanotherpart,thatwouldbethehandofanyplayer.OntheShuffleCards().Wewillgenerateatime-basedseedwhichwewilluseforshufflingthedeckinarandomorder.Also,lookatthe

Dealer()function.Ithasanestedloop(aloopinsideanotherloop)and,withthis,wegeneratethecards.From1to12andeachfrom1to4.Afterthis,eachcardisinsertedtothedeckandnowthedeckiscreated!Now,themostimportantpart,themainfunction:#include<iostream>#include<string>#include<vector>#include"player.h"#include"card.h"#include"dealer.h"usingnamespacestd;//NumberofcardsallowedinhandintCardNumber=5;intmain()

{

//CreateplayersPlayerplayer1;Playerplayer2;player1.name="CPU";stringname;cout<<"Enteryourname:";cin>>name;player2.name=name;

DealertheDealer;theDealer.ShuffleCards();//Givecardstotheplayersfor(inti=0;i!=CardNumber;i++){player1.GetCard(theDealer.GiveCard());player2.GetCard(theDealer.GiveCard());}player2.ShowHand();cout<<"\n";player1.ShowHand();return0;

}

Therearenounknownlibraries.Rememberthatwemustaddallofourclassheaders.ThereistheconstantCardNumber.Itwillbeusedbythedealerforgivingcards.Whenthemainfunctionstarts,twoplayersarecreated.Weassignplayer1thename“CPU”andforplayer2,thenamewillbegivenbytheuser.Afterthiswecreatethedealer(andbycreatingthedealer,alsothedeckiscreated)andtellthedealertoshufflecards.Now,from0toCardNumber,thedealerwillobtainacardforeachplayer,removeitfromthedeckandgiveittothehandoftheplayer.Afterthis,bothhandsareshownandtheoutcomeofthegamecanbedetermined.Inthisexample,itcanbeveryeasytounderstandhowallofthesereallifeobjectsareabstractedandtakentoaprogrammingparadigmlikeC++.Herethereisnofunctionallogic,onlyOOPlogic.

CHAPTER10:WHATTODONEXT

Upuntilnow,wecoveredsomebasicandintermediatestuffconcerningC++.However,inordertomasterC++,therearemorespecializedtopicsthatshouldbelearned.

Memorymanagement:Theuseofthememoryavailablefromtheoperatingsystemintoourobjects.Thekeywordsnewanddelete.Withthesetwokeywords,youcanmanagehowmanymemoryisbeingused,assignwhenandtowhomassignmemoryandevenoptimizeyourprograms.

StandardTemplateLibrary:Inthiscoursewecoveredonlytwotemplates:mapandvector.However,theC++’sSTLiswaybeyondthisthesetwoobjects.Structureslikethestack,queue,list,dequeandmorearebuilt-inwithinC++.

Iterators:TheiteratorsisthewaythatC++loopsthroughthetemplatesbutdonotuseindexes.Instead,theiteratorsadapttotheneededcontainer.

Pointers:PointersareaveryimportantpartofC++andwillallowyoutohaveabettermemorymanagementandcreatemultipleobjectssavinghugeamountsofmemory.

Stringmanagement:Multipleoperationscanberealizedusingstrings.Searchforpatterns,complexconcatenation,tokenizetokens,processingstrings,replacingtotallyorpartiallystrings,etc.

FundamentsofOOP:AlthoughwecoveredsomepointsfromOOPinthesampleprojects,thiscoursewasnotaboutOOP.Soitwouldbeagoodideatocoverfull

OOPtheoryinordertogeneratebetterdesignofprogramming.Someconceptswouldbeclass,abstraction,member,memberfunctions,simpleinherence,multipleinherenceandevenpolymorphism.

Createyourownlibraries:Aswesawonthecourse,youcangenerateyourown.hand.cppfiles.Hereweusedthemasexternallinkingforclasses.Butitcanbealsoimplementedwithyourownhome-madefunctions.Youmighthavefunctionsthatyouneedtousemultipletimesanddonotwanttohavetorewritethemseveraltimes.So,agoodideawouldbetoimplementallofthesefunctionsinasingle.cppfileandaddittoafutureproject.

Ifyoucoverallofpointsmentionedhere,youcanmoveontomoreadvancedfeatureslike:

Templates

Operatoroverloading

Complexfileprocessing

Graphicalprogramming

Onwindows:MicrosoftFoundationClasses

OnLinux:GTK+orQT

Even,withgraphicalprogramming,thereistheOpenGLopensourceprogramming.WithOpenGLyoucangenerate2Dand3DgraphicsusingC++.Inthe2Dmode,youcandrawmultiplefiguresusingvertexandmatrix.Youcanaddtextures,colorsandrefreshscreenwheneveryouwant.Inthe3Dmode,youcandesignyourown3Denvironments,definetexturesand3Dmodels.Atthis

point,animationsbecomeaccessible.Also,inbothmodes,youcanenabletheuseofthekeyboardandassignactionswitheachkey.WithOpenGLyoucanalsodesignvideogames,fromtheeasiesttothehardest.Itdependsonyourprogrammingskills.Moreover,OpenGLalsoenablesyoutoaddbackgroundaudios,andallofthisusingC++.However,youshouldtakenotethatOpenGLrunswellontheMicrosoftVisualStudiocompiler.ExtraconfigurationsmightbeneededintheGNUG++compiler.Asyoucansee,thelimitinC++programmingisuptoyourimagination.

CONCLUSION:

Afterthetopicswehavecovered,youcanhaveaclearersceneofhowC++programmingisdeveloped.WehavetriedtohaveanappliedaspectoftheapplicationsofC++.Thereasonisthatmanytimes,theuserdoesnotunderstandhowallthepiecescanworktogetherasacompletesystem.Sowehavebeencarefulintheappliedfocusforthiscourse.Asyoumighthavenoticed,thecomplexprogramsare,attheend,aremadeusingthesamebasicinstructionsexplainedinchapterone.Oneexampleofthisisthecreationofamenu:herewehavevariabledeclaration,aninfiniteloop,aswitchstatementandsomeinput.Usingthesebasicstructureswecanbuildthemenuandmanymorestuff.Onethingthatwehavetoremember(andthatmanypeopledon’tsee)isthattheconsoleisnottheonlyoutput.Youmightthinkthattheconsoleiscompletelyuselessandisnotattractive.And,inacertainway,thisisright.Theconsoleisnottheappropriateinputandoutputsystemformostprogramminginthesedays.However,remember:thepowerofC++isitsspeed,itscomplexityanditsSTL.Theinputandoutputsystemcanbealwayschanged:sometimesitcanbefromconsole,othertimescanbeafile,andanotheragraphicaluserinterface(GUI)orwhateveryouwant.Butdon’tbemistakenbythefalsefactthattheprogramsthatareuglyarecompletelyuseless.Havingthiscourse,youcanadvancetoamorecomplexgraphicalsystem,whereyoucanmakemorecomfortablesoftwarewhilestillhavingthepowerofC++.ExamplesofthisisGTK+orQT.WiththeseC++expansions,youcandesigngraphicalinterfacesforcomplementingyourprojects.ThiscoursealsocoveredsomefeaturesthatC++inheritsfromitspredecessor,C,likethemathfunctions.Thesearenottheonlyones.YoucandiveupintothecompleteClibraryandfindabunchmoreoftoolstouseinyourC++programming,justremembertomakethepropertypeconversions.Afterthiscourse,youarenowabletodevelopyourownsolutions.Andyouarenotlimitedbythesolutions.Now,youcandofileprocessing,datastorage,reportcreation,datatypeconversionandmorefeaturesthatarewidelyusedforcalculations.Somethinghastobesaid:plaintextisnotthebestwaytosaveinformation.Theoptimalwaywouldbeadatabase.Butthisisamorecomplex

tocoverinabasiccourse.However,withthisbasicknowledgeofdatastorage,youcanmoveontoabetterstoringtechnique.Afterthispoint,itisintheinterestofthiscoursethatyouarenowabletointerpretC++codeandtoprovidesolutionsusingthelanguage.Manyresourcesareavailableontheinternet,likereferencepages,thatcancomplementallofyourC++knowledgeandthatyoumightnow,withtheconceptsthatwehavecovered,understandanimplementnewfunctionalities.Nowthequestionwouldbe,whatareyougoingtodowithyournewlyacquiredknowledge?

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