chapter56e 函数.docx
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chapter56e函数
TRUE/FALSE
1.Avoidfunctioncanreturnanyvalue
ANSWER:
FALSE
2.Avoidfunctioncanbeusedinanassignment.
ANSWER:
FALSE
3.Avoidfunctionmaynotbeusedinanoutputstatement.
ANSWER:
TRUE
4.Functionscanreturnatmostonevalue.
ANSWER:
TRUE
5.Thefollowingislegalinavoidfunction
return;
ANSWER:
TRUE
6.Inafunctionwithcall-by-referenceparameters,thevaluesoftheactualargumentsarepassedtothefunction.
ANSWER:
FALSE,Theactualvariables（ormorepreciselytheirmemoryaddresses）arepassed.
7.Inafunctionwithcall-by-referenceparameters,anychangestotheformalparameterswillchangetheactualargumentspassedtothefunction.
ANSWER:
TRUE
8.Itisacceptabletohavebothcall-by-valueandcall-by-referenceparametersinthesamefunctiondeclaration.
ANSWER:
True
9.Itisillegaltocallotherfunctionsfrominsideafunctiondefinition.
ANSWER:
FALSE
10.Astubisafunctionthatiscompletelydefinedandwelltested
ANSWER:
FALSE
SHORTANSWER
1.A___________isamainprogramthatonlychecksthatfunctionsexecutecorrectly.
ANSWER:
driver
2.Thevaluesorvariableslistedinthefunctiondeclarationarecalled_________tothefunction.
ANSWER:
（formal）parameters
3.Giventhefollowingfunctiondefinitionfragment,forwhichvaluesofmyIntshouldthefunctionbetested?
intdoSomething（intmyInt）
{
if（myInt<0）
{
//dosomestuffhere
}
}
ANSWER:
-1,0,1
4.Whentheaddressoftheactualargumentispassedtotheformalparameter,thisiscalled__________________________
ANSWER:
call-by-reference–or-pass-by-reference
5.Ifwewanttotestifagivenfunctionworkscorrectly,wewouldwritea_________totestit.
ANSWER:
driver
6.Thevariablespassedafunctionarecalled_________.
ANSWER:
arguments
7.Whatisthecorrectwaytocallthefollowingfunction?
_________________________
voidsetDisplay（）;
ANSWER:
setDisplay（）;
8.Afunctionthatdoesnotreturnavalueisknownasa________function.
ANSWER:
void
9.Whattypeofvaluedoesavoidfunctionreturn?
____________
ANSWER:
nothing
10.Whatsymbolisusedtosignifythataparameterisareferenceparameter?
______
ANSWER:
ampersand（&）
11.Whatisthecorrectwaytocallthefollowingfunction?
AssumethatyouhavetwovariablesnamedintArgument（int）andfloatArgument（float）.
voiddoThings（floatx,inty）;
ANSWER:
doThings（floatArgument,intArgument）;
12.Usingfunctionsinaprogramiscalled_____________.
ANSWER:
proceduralabstraction
13.preandpostconditionsforafunctionshouldbewritten（before/after）thefunctiondefinitioniswritten.
ANSWER:
before
14.A________isasimplifiedversionofafunctionusedtotestthemainprogram.
ANSWER:
stub
15.Testingaprogramwithvaluesthatareclosetovaluesthatwillchangetheexecutionofaprogramiscalled_________________.
ANSWER:
boundarytesting
MULTIPLECHOICE
1.WhichofthefollowingisalegalcalltothedisplayOutputfunction?
voiddisplayOutput（inttotal）;
a.voiddisplayOutput（myTotal）;
b.displayOutput（intmytotal）;
c.displayOutput（myTotal）;
d.cout<ANSWER:
C
2.Theprecondition（s）forafunctiondescribe:
a.Whatistrueafterthefunctionisexecuted
b.Whatthefunctiondoes
c.Howtocallthefunction
d.Whatmustbetruebeforethefunctionexecutes
ANSWER:
D
3.Whichofthefollowingistrueforavoidfunction?
a.Therecannotbeareturnstatement.
b.Thevalueofvoidshouldbereturned.
c.Thevalueof0shouldbereturned.
d.Nothingisreturned.
ANSWER:
D
4.Call-by-referenceparametersarepassed
a.nothing
b.theactualargument.
c.thevalueintheactualargument.
d.theaddressoftheargument.
ANSWER:
B（我觉得B和D都对啊。
。
。
）？
？
？
5.Ifyouneedafunctiontogetboththenumberofitemsandthecostperitemfromauser,whichwouldbeagoodfunctiondeclarationtouse?
a.int,floatgetData（）;
b.intgetData（floatcost）;
c.voidgetData（intcount,floatcost）;
d.voidgetData（int&count,float&cost）;
ANSWER:
D
6.Whatistheoutputofthefollowingfunctionandfunctioncall?
voidcalculateCost（intcount,float&subTotal,float&taxCost）;
floattax=0.0,
subTotal=0.0;
calculateCost（15,subTotal,tax）;
cout<<"Thecostfor15itemsis"<<<",andthetaxfor"<//endoffragment
voidcalculateCost（intcount,float&subTotal,float&taxCost）
{
if（count<10）
{
subTotal=count*0.50;
}
else
{
subTotal=count*0.20;
}
taxCost=0.1*subTotal;
}
a.Thecostfor15itemsis3.00,andthetaxfor3.00is0.30;
b.Thecostfor15itemsis0.00,andthetaxfor3.00is0.00;
c.Thecostfor15itemsis0.00,andthetaxfor3.00is0.30;
d.Thecostfor15itemsis3.00,andthetaxfor3.00is0.00;
ANSWER:
A
7.Whatistheoutputofthefollowingfunctionandfunctioncall?
voidcalculateCost（intcount,float&subTotal,floattaxCost）;
floattax=0.0,
subtotal=0.0;
calculateCost（15,subtotal,tax）;
cout<<"Thecostfor15itemsis"<<<",andthetaxfor"<//endoffragment
voidcalculateCost（intcount,float&subTotal,floattaxCost）
{
if（count<10）
{
subTotal=count*0.50;
}
else
{
subTotal=count*0.20;
}
taxCost=0.1*subTotal;
}
a.Thecostfor15itemsis3.00,andthetaxfor3.00is0.30;
b.Thecostfor15itemsis0.00,andthetaxfor3.00is0.00;
c.Thecostfor15itemsis0.00,andthetaxfor3.00is0.30;
d.Thecostfor15itemsis3.00,andthetaxfor3.00is0.00;
ANSWER:
D
8.Whichofthefollowingfunctionprototypesarenotvalid?
a.voiddoSomething（int&x,inty）;
b.voiddoSomething（int&x,int&y）;
c.voiddoSomething（intx,inty）;
d.allarenotvalid
e.allarevalid
ANSWER:
E
9.Youshouldmakeaparameterareferenceparameterif:
a.Youneedthefunctiontochangethevalueoftheargumentpassedtothefunction.
b.youneedtobeabletochangethevalueoftheparameterinthefunction,butnotthevalueoftheargument.
c.Always.
d.Ifanyoftheotherparametersarereferenceparameters.
ANSWER:
A
10.Whichofthefollowingaretrue?
a.afunctioncancallanotherfunction.
b.aslongasthefunctionisdefinedanywhereinyourprogram,itcanbeusedanywhereelse.
c.afunctiondefinitioncancontainanotherfunctiondefinition.
d.ifyouhavefunctionprototypes,theorderinwhichyoudefineyourfunctionsisimportant.
ANSWER:
A
11.Thepostconditionofafunction
a.determineshowthefunctionwillcompleteitsjob.
b.tellswhatmustbetruebeforethefunctionexecutes.
c.declaresthefunctionforthecompiler.
d.tellswhatwillbetrueafterthefunctionexecutes.
ANSWER:
D
12.Whatisthevalueofchoiceafterthefollowingstatements?
voidgetChoice（int&par_choice,inpar_count）;
intchoice,count=3;
getChoice（choice,count）;
voidgetChoice（int&par_choice,inpar_count）
{
if（par_count<0）
par_choice=0;
if（par_count=0）
par_choice=-1;
else
par_choice=99;
return;
}
a.3
b.0
c.–1
d.99
ANSWER:
D
13.Whatiswrongwiththefollowingfunctionbody?
voidcalculate（intcount,floatprice,float&cost）
{
if（count<0）
cost=0.0;
else
cost=count*price;
return;
}
a.voidfunctionsmaynothaveareturnstatement.
b.voidfunctionsmustreturnavalue
c.nothing
d.cannotmixreferenceandvalueparameters
ANSWER:
C
14.Ifyouweretowriteafunctionfordisplayingthecostofanitemtothescreen,whichfunctionprototypewouldbemostappropriate?
a.voiddisplay（）;
b.voiddisplay（floatmyCost）;
c.intdisplay（floatmyCost）;
d.floatdisplay（）;
ANSWER:
B
15.Giventhefunctiondefinition
voidsomething（inta,int&b）
{
intc;
c=a+2;
a=a*3;
b=c+a;
}
whatistheoutputofthefollowingcodefragmentthatinvokessomething?
（Allvariablesareoftypeint.）
r=1;
s=2;
t=3;
something（t,s）;
cout<a.1143
b.1103
c.5143
d.1149
e.noneoftheabove
ANSWER:
A
16.Giventhefollowingfunctiondeclarationandlocalvariabledeclarations,whichofthefollowingisnotacorrectfunctioncall?
intmyInt;
floatmyFloat;
charch;
voidsomeFunction（int&first,floatsecond,charthird）;
a.someFunction（1,2.0,ch）;
b.someFunction（myInt,myFloat,ch）;
c.someFunction（myInt,2.0,'c'）;
d.someFunction（myInt,myFloat,'1'）;
ANSWER:
A
17.Giventhefollowingfunctiondefinition
voidshift（int&a,int&b）
{
a=b;
b=a;
}
Whatistheoutputafterthefollowingfunctioncall?
intfirst=0,second=10;
shift（first,second）;
cout<a.010
b.100
c.00
d.1010
ANSWER:
D
18.Whatistheoutputofthefollowingcodefragments?
inttrial（int&a,intb）
{
if（b>a）
{
a=b;
return–a;
}
else
{
return0;
}
}
floatx=0,y=10,z;
z=trial（y,x）;
cout<a.–1000
b.0100
c.1000
d.0010
ANSWER:
D
19.Whenavoidfunctioniscalled,itisknownas
a.Anoutputfunction.
b.Areturnedvalue.
c.Anexecutablestatement.
d.Acomment
ANSWER:
C
20.Ifafunctionneedstomodifymorethanonevariable,itmust
a.bepassbyvalue
b.beavoidfunction
c.returnallvaluesneeded
d.beacallbyreferencefunction
ANSWER:
D
21.Inthefollowingfunction,whatispassedtothefirstparameter?
voidf1（int&value1,intvalue2）;
intx,y;
f1（x,y）;
a.Thevalueofx
b.nothing,itisavoidfunction
c.thevalueofy
d.thevariablex（oritsmemorylocation）
ANSWER:
D
22.Giventhefollowingfunctiondefinitionsandprogramfragments,whatistheoutput?
voidf1（int&z,int&q）
{
inttemp;
temp=q;
q=z;
z=temp;
}
voidf2（int&a,int&b）
{
if（a<
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