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7/31/2019 Oct 29 CS31
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------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------stringphone;for(;;){cout
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*****cantreturntwodoubles,soweusedreferencevariables
intmain(){doubler;r:5doubleangle;angle:0...//getvaluesforrandangledoublex;x:5:xx//onceyoureturntothefunctionyoucantcallx...xxanymore.doubley;y:0:yypolarToCartesian(r,angle,x,y);//nowxandyhavetherihtvalues(wrongg)...doublex2;x2:10:xxpolarToCartesian(2*r,angle,x2,y);//wrong}
rho:10theta:0xx:yy:0------->doendupwiththerightvalues,butthesefourlocalvariablesgoawaywhenyouleavethefunctionvoidpolarToCartesian(doublerho,doubletheta,doublexx,doubleyy)//shouldbevoidpolarToCartesian(doublerho,doubletheta,double&x,double&y)//canalsobedouble&xx,double&yy
{x=rho*cos(theta);y=rho*sin(theta);}
Whydoesntthiswork?*****double&meansreference-doubleoranother-name-for-some-double******************canbedouble&xx,akaspaceasdesired*****cannotputacomputationintoareferencevariable-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------------------k:(copy)3intsquare(intk)//preferablebecauseitismoreflexible{
returnk*k;}
voidsquareTheArgument(int&j){j*=j;}
intmain()
{intn;cin>>n;n:9intm;m:81...m=square(n);m=square(m);---------->thesquarefunctiondidntchangem,theassignmentdidcout
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...}---------------------------------------------------------------------------------------------------------::::FORPROJECT3::::---------------------------------------------------------------------------------------------------------inttraversePath(...,...,...,...,...,int&nsteps);//goalistoimplementtraversePathliketraverseSegment---------------------------------------------------------------------------------------------------------12n3eisavalidpath....12n3e123n3enotavalidpath*****pathsegmentsare1or2digitsfollowedbythedirectionlol*****78n3e78n3e,wellformedpathbutnottraversable12nemptystringisalsoawellformedpath,wontgoanywhere----------------------------------------------------------------------------------------------------------dothefunctionexerciseswootwootdothewriteuponcharactersandstringswootwoot-----------------------------------------------------------------------------------------------------------1n3eisnotapathsegment
@1ne3eisnotapathsegment----------------------------------------------------------------------------------------------------------::::TABLESMESASMESAS::::----------------------------------------------------------------------------------------------------------
boolisValidDate(inty,intm,intd){intdaysInMonth[12]={31,28,31,30,31,30,31,31,30,31,30,31};
...if(m12||dLEAVEEE...opposedtobreak,whichbreaksaloop/swi
tchstatementandcontinuewithrestoffunctionif(m==2){....return...;}returnd
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