大数据基础技能试题及答案Word文件下载.docx
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homedirectory"
Stringt=s-"
directory"
5.Whicharesyntacticallyvalidstatementati=m;
B.i=b;
C.i=;
D.i=（30）;
E.i=.
6.Whichlayoutmanagerisusedwhentheframeisresizedthebuttons'
spositionintheFramemightbechanged
A.BorderLayout
B.FlowLayout
C.CardLayout
D.GridLayout
7.Giventhefollowingcodefragment:
1）publicvoidcreate（）{
2}VectormyVect;
3}myVect=newVector（）;
4}}
Whichofthefollowingstatementsaretrue
A.Thedeclarationonline2doesnotallocatememoryspaceforthevariablemyVect.B.Thedeclarationonline2allocatesmemoryspaceforareferencetoaVector
object.
C.Thestatementonline2createsanobjectofclassVector.
D.Thestatementonline3createsanobjectofclassVector.
E.Thestatementonline3allocatesmemoryspaceforanobjectofclassVector
8.Whichofthefollowingansweriscorrecttoexpressthevalue8inoctalnumber
A.010
B.0x10
C.08
D.0x8
9.WhicharenotJavakeywords
A.TRUEB.sizeofC.constD.superE.void
10.Whichofthefollowingstatementsaretrue
A.Theequals（）methoddeterminesifreferencevaluesrefertothesameobject.
B.The==operatordeterminesifthecontentsandtypeoftwoseparate
objects
match.
C.Theequals（）methodreturnstrueonlywhenthecontentsoftwoobjectsmatch.
D.TheclassFileoverridesequals（）toreturntrueifthecontents
andtype
of
two
separateobjectsmatch.
11.Whichstatementsaboutinheritancearetrue
A.InJavaprogramminglanguageonlyallowssingleinheritance.
B.InJavaprogramminglanguageallowsaclasstoimplementonlyoneinterface.
C.InJavaprogramminglanguageaclasscannotextendaclassandimplementainterfacetogether.
D.InJavaprogramminglanguagesingleinheritancemakescodemorereliable.
12.
1）classPerson{
2}publicvoidprintValue（inti,intj）{/*⋯*/}
3}publicvoidprintValue（inti）{/*...*/}
5）publicclassTeacherextendsPerson{
6}publicvoidprintValue（）{/*...*/}
7}publicvoidprintValue（inti）{/*...*/}
8}publicstaticvoidmain（Stringargs[]）{
9}Persont=newTeacher（）;
10}（10）;
11}}
12}}
Whichmethodwillthestatementonline10call
A.online2
B.online3
C.online6
D.online7
13.WhicharenotJavaprimitivetypesA.short
B.BooleanC.unit
D.float
14、Themethodresume（）isresponsibleforresumingwhichthread'
sexecution
A.Thethreadwhichisstoppedbycallingmethodstop（）
B.Thethreadwhichisstoppedbycallingmethodsleep（）
D.Thethreadwhichisstoppedbycallingmethodsuspend（）
15.Whichofthefollowingrangeofintiscorrect
A.-2^7
–2^7-1
B.0–2^32-1
C.-2^15
–2^15-1
D.-2^31
–2^31-1
16.WhichkeywordshouldbeusedtoenableinteractionwiththelockofanobjectTheflagallowsexclusiveaccesstothatobject.
A.transient
B.synchronized
C.serialize
D.static
17.Whichisthereturntypeofthemethodmain（）A.int
B.void
C.booleanD.static
18.Giventhefollowingcode:
if（x>
0）{"
first"
）;
}
elseif（x>
-3）{"
second"
else{"
third"
Whichrangeofxvaluewouldprintthestring"
A.x>
0
B.x>
-3
C.x<
=-3
D.x<
=0&
x>
19、Whichofthefollowingansweriscorrecttoexpressthevalue10inhexadecimalnumber
A.0xA
B.0x16
C.0A
D.016
20.Whichstatementsaboutthegarbagecollectionaretrue
A.Theprogramdevelopermustcreateathreadtoberesponsibleforfreethememory.
B.Thegarbagecollectionwillcheckforandfreememorynolongerneeded.C.Thegarbagecollectionallowtheprogramdevelopertoexplicityandimmediatelyfreethememory.
D.Thegarbagecollectioncanfreethememoryusedjavaobjectatexpecttime.
21、Giventhefollowingcode:
1）publicclassTest{2}intm,n;
3}publicTest（）{}
4}publicTest（inta）{m=a;
5}publicstaticvoidmain（Stringarg[]）{
6}Testt1,t2;
7}intj,k;
8}j=0;
k=0;
9}t1=newTest（）;
10}t2=newTest（j,k）;
Whichlinewouldcauseoneerrorduringcompilation
A.line3
B.line5
C.line6
D.line10
22、Giventheuncompletedcodeofaclass:
classPerson{
Stringname,department;
intage;
publicPerson（Stringn）{name=n;
publicPerson（Stringn,inta）{name=n;
age=a;
publicPerson（Stringn,Stringd,inta）{
."
partoftheconstructor
A.Person（n,a）;
B.this（Person（n,a））;
C.this（n,a）;
D.this（name,age）.
23、WhichofthefollowingstatementsaboutvariablesandtheirscopesaretrueA.Instancevariablesaremembervariablesofaclass.
B.Instancevariablesaredeclaredwiththestatickeyword.
C.Localvariablesdefinedinsideamethodarecreatedwhenthemethodisexecuted.
D.Localvariablesmustbeinitializedbeforetheyareused.
24、publicvoidtest（）{
try{oneMethod（）;
"
condition1"
}catch（ArrayIndexOutOfBoundsExceptione）{
condition2"
}catch（Exceptione）{"
condition3"
}finally{
finally"
}
WhichwilldisplayifoneMethodrunnormally
A.condition1
B.condition2
C.condition3
D.finally
25、Giventhefollowingcode:
publicclassTest{
voidprintValue（intm）{
do{"
Thevalueis"
+m）;
while（--m>
10）
publicstaticvoidmain（Stringarg[]）{
inti=10;
Testt=newTest（）;
（i）;
Whichwillbeoutput
A.Thevalueis8
B.Thevalueis9
C.Thevalueis10
D.Thevalueis11
26、Whichofthefollowingstatementsaboutdeclarationaretrue
A.Declarationofprimitivetypessuchasboolean,byteandsoondoesnotallocatememoryspaceforthevariable.
B.Declarationofprimitivetypessuchasboolean,byteandsoonallocatesmemoryspaceforthevariable.
C.DeclarationofnonprimitivetypessuchasString,Vectorandsoondoesnot
allocatememoryspacefortheobject.
D.DeclarationofnonprimitivetypessuchasString,Vectoranssoonallocatesmemoryspacefortheobject.
27、IntheJavaAPIdocumentationwhichsectionsareincludedinaclassdocument
A.Thedescriptionoftheclassanditspurpose
B.Alistofmethodsinitssuperclass
C.Alistofmembervariable
D.Theclasshierarchy
28、Giventhefollowingcode:
1）publicvoidmodify（）{
2）inti,j,k;
3）i=100;
4）while（i>
0）{
5）j=i*2;
6）（"
Thevalueofjis"
+j）;
7）k=k+1;
8）i--;
9）}
10}}
Whichlinemightcauseanerrorduringcompilation
A.line4
B.line6
C.line7
D.line8
29、Whichofthefollowingstatementsaboutvariablesandscopearetrue
A.Localvariablesdefinedinsideamethodaredestroyedwhenthemethodisexited.
B.Localvariablesarealsocalledautomaticvariables.
C.Variablesdefinedoutsideamethodarecreatedwhentheobjectisconstructed.
D.Amethodparametervariablecontinuestoexistforaslongastheobjectis
neededinwhichthemethodisdefined.
30、Aclassdesignrequiresthatamembervariablecannotbeaccessibledirectlyoutsidetheclass.Whichmodifiershouldbeusedtoobtaintheaccesscontrol
A.public
B.nomodifier
C.protected
D.private
31、Giventhefollowingcodefragment:
1）Stringstr=null;
2）if（（str!
=null）&
&
（）>
10））{3}"
morethan10"
5）elseif（（str!
（）<
5））{
6}"
lessthan5"
7}}
8）else{"
end"
Whichlinewillcauseerror
A.line1
B.line2
C.line5
32、WhichstatementsaboutJavacodesecurityaretrue
A.Thebytecodeverifierloadsallclassesneededfortheexecutionofaprogram.
B.Executingcodeisperformedbytheruntimeinterpreter.
C.Atruntimethebytecodesareloaded,checkedandruninaninterpreter.
D.Theclassloaderaddssecuritybyseparatingthenamespacesfortheclasses
ofthelocalfilesystemfromthoseimportedfromnetworksources.
33、Giventhefollowingcode:
publicclassPerson{
intarr[]=newint[10];
publicstaticvoidmain（Stringa[]）{
Whichstatementiscorrect
A.Whencompilationsomeerrorwilloccur.
B.Itiscorrectwhencompilationbutwillcauseerrorwhenrunning.
C.Theoutputiszero.
D.Theoutputisnull.
34、publicclassParent{
publicintaddValue（inta,intb）{
ints;
s=a+b;
returns;
classChildextendsParent{
WhichmethodscanbeaddedintoclassChild
A.intaddValue（inta,intb）{.}
B.publicvoidaddValue（）{.}
C.publicintaddValue（inta）{.}
D.publicintaddValue（inta,intb）throwsMyException{.}
35、Whichstatementsaboutthreadaretrue
A.Onceathreadiscreated,itcanstarrunningimmediately.
B.Tousethestart（）methodmakesathreadrunnable,
butitdoesnotnecessarily
startimmediately.
C.Whenathreadstopsrunningbecauseofpre-emptive,
it
isplacedatthefront
endoftherunnablequeue.
D.Athreadmayceasetobereadyforavarietyofreasons.
36、Amembervariabledefinedinaclasscanbeaccessedonlybytheclassesinthe
samepackage.Whichmodifiershouldbeusedtoobtaintheaccesscontrol
A.private
C.public
D.protected
37、ApublicmembervairablecalledMAX_LENGTHwhichisinttype,thevalueofthevariableremainsconstantvalue
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