java基礎(chǔ)習(xí)題和解答1.監(jiān)聽接口中的方法返回值是

Java習(xí)一、單選題（54道x1y2z3y+=z--/++x-x的值是？(1項 doublemyresult=Math.sqrt(1000)； 在Java中，要處理Button類對象的，以下各項中，哪個是可以處理這個的接（publicclasspublicstaticvoidmain(Stringargs[]){intage;}}編譯，運行后輸出：Theageis 在Java語言中，類Worker是類 （i的定義中，正確的是。(1項finalstaticintstaticfinal finalfloat1--0B C D電子商務(wù)有許多分類，其中 toC是指 ) D、企業(yè)與電子商務(wù)有許多分類，其中 toB是指 ) B、Internet商 C、Intranet商 B、廣域 在一個由客戶端，協(xié)議、中間層（DMZ、域及企業(yè)內(nèi)部網(wǎng)構(gòu)成的電子商務(wù)系統(tǒng)中，一般情況下，協(xié)議會允許哪個/些協(xié)議通過？ 一個電子商務(wù)解決方案由客戶端、協(xié)議、應(yīng)用服務(wù)器、域和企業(yè)內(nèi)部網(wǎng)幾要的。在這種需求下，第二層需要刪除么？不能刪除。使用第二層可以改善安全。第二層能夠防止外INTERNET用戶直接企業(yè)內(nèi)部服務(wù)器 DB2LotusIBM電子商務(wù)框架中，會推薦使用下面哪一種標準 D.下面那種技術(shù)可以與基于瀏覽器的WEB應(yīng)用共同協(xié)作，使得某些錯誤能夠直接在終端用戶的客戶端處理而無需在WEB服務(wù)器端處理？A. B. C. 一種技術(shù)是基于SGML的，并能滿足客戶的這一需求？ B. C. D.ABCDABCDABCDpublicclassHoltextends{privateStringpublicstaticvoidmain(String{Holth=newHolt();}Holt()}Holt(Strings)sThreadName=}{return}publicvoidgo()Holtfirst=newHolt("first");Holtsecond=newHolt("second");}publicvoidstart()for(inti=0;i<2;{System.out.println(getThreadName()+i);try{}catch(InterruptedException{}}}}first0second0first0輸出offirst0first1second0AArrayListmyList=newObject（；BListmyList=newArrayList（；CArrayListmyList=newList（；DListmyList=newList（；ABCD Stringname=dir.getName();newVector(5,ABClongDABCD};public bepublicstaticvoidmain(String bem=new m.go(newTuring(){}publicvoidgo(Turingt)}}{publicvoidrun()for(inti=0;i<2;{}}}providesthatcapability?A.java.uil.MappublicclassMyClasspublicstaticvoidmain(String{intanar[]=newint[]{1,2,3};}}12longnumber=longnumber=longnumber=longnumber=publicclassTestpublicstaticvoidmain(String{Strings=newString("Bicycle");intiBegin=1;chariEnd=}}error:nomethodmatching類publicclassex2publicstaticvoidmain(String[]{ {}}}0123678012346785Stringstr=if((str!=null)&&(str.length()>10))}elseif((str!=null)&(str.length()<5))}AlineBlineClineDlineStrings1=newString("o");Strings2=newString("there");Strings3=newString();s3=s1+s3=s1&s3=s1&&ABCDSystem.out.println(4|A.B.C.D. switch(a+b*3.0 switch switch(a%b 二 多選題（54道publicclasspublicstaticvoidmain(Stringargv[]){inti;intinner:for(j=1;j<3;{ifSystem.out.println("Valuefori="+i+"Valueforj="}}}Valuefori=1valueforValuefori=2valueforValuefori=2valueforValuefori=3valuefor{casecase2:case}A.B.C.D.E.classpublicvoidamethod(inti){}publicclassScopeextendspublicstaticvoidmain(String}voidamethod(inti)throwsExceptionvoidamethod(longi)throwsExceptionvoidamethod(longpublicvoidamethod(inti)throwsExceptionAinta[][]=newBinta[10][10]=newCinta[][]=newDint[][]a=newEint[]a[]=newpublicclassMyClass1publicstaticvoidmain(Stringargv[]){/*XX*classMyInner}ABCDinterfaceAintmethod1(inti);intmethod2(int}A.classBimplementsAintmethod1(){}intmethod2(){}}B.classBintmethod1(inti){}intmethod2(intj){}C.classBimplementsAintmethod1(inti){}intmethod2(intj){}D.classBextendsAintmethod1(inti){}intmethod2(intj){}E.classBimplementsAintmethod2(intj){}intmethod1(inti){}publicstaticvoidmain(Stringargs[]){Floatf=newFloat(4.2f);Floatc;Doubled=newDouble(4.2);floatfl=4.2f;}ABCD后一個元素，下面不正確的代碼是()。A.intAB.intA=1;C.intA=1;D.intA=1;AA CDE G publicvoidhai(intBhai(inta,int publichai(intDinthai(intc,int intFinthai(Stringbreakcontinuegotoif(A>B }class{privateintpublicintsetVal(int{}}class{privatestaticintVal;publicintsetVal(intVal){}}class{privateintpublicstaticintsetVal(int{}}class{privatestaticintpublicstaticintsetVal(int{}}publicvoidhai(inta,intprotectedvoidhai(inta,intpublichai(intinthai(intc,intintinthai(StringIntegers=newInteger(9);Integert=newInteger(9);Longu=newLong(9);publicstaticvoidmain(Stringargs[]){try{}} ABCDEFfinalclass{privateinta=1;intb=2;}classSecondextends{publicvoidmethod(){System.out.println(a+b);}}B因為變量a是private,所以在其他類中不能aCSecond不能繼承FirstD關(guān)鍵字finalabcdint型的變量，并已賦值，下列表達式的結(jié)果屬于邏輯值的是()。A.a!=b&c%d<B.a++=D.i,jxdoublex類的構(gòu)造方法中正確的是doublex(doublek){i=k;returni;x(doublem,doublen){i=m;j=n;x(){i=0;j=0x(doublek){i=k;switch(s)} charc='\' charc= charc='\ucafe' charc='0x001'ABinti=CDcharc=Es=s inti[][]=new inti[10][10]=newinti[][]=newint[][]i=newcharc[][]; String[]s; Strings[50]; Objects[50];base{publicint{int}}publicclasssubextends{privatefloatpublicstaticvoidmain(Stringargs[]){baseb=newbase();floatg;int}} ()publicintx(){...publicstaticintx(doubley){...voidx(doubled){...publicstaticx(doublea){...A．$ C.D.E.A.4B.4C.D.執(zhí)行下列代碼后,Strings=newAs[10]Bs[9]Cs[0]Ds.length()A.privatebyteresult=if(result){//dosomething...if(result!=0){//sosomething...result=AStrings="你好";inti=3;BStrings="你好";inti=3;if(i==sCStrings="你好";inti=3;DStrings="你好";inti=3;Strings=null;intABCD哪個布局管理器使用的是組件的最佳尺寸（preferredABCDCardLayoutApublicclassXimplementsRunable{publicvoid }BpublicclassXimplementsThread{publicvoid }CpublicclassXimplementsThread{publicint }DpublicclassXimplementsRunable{protectedvoid }E.publicclassXimplementsThread{publicvoid }ABCcase1:System.out.println(“Testcasecase3:System.out.println(“Test2”);break;}A.B.C.D.publicclassParentpublicintaddValue(inta,int{ints;s=a+b;return}}classChildextendsParent}intaddValue(inta,intb){//dopublicvoidaddValue(){//dopublicintaddValue(inta){//dopublicintaddValue(inta,intb)throwsMyException{//doStrings="Gonewiththewind";Stringt="good";Stringk=s+Strings="Gonewiththewind";Stringt;t=s[3]+Strings="Gonewiththewind";Stringstandard=s.toUpperCase();Strings="homedirectory";Stringt=s-"directory";example(){}{System.out.println("Testfinally{System.out.println("Test}BTestCTestDTestA3publicclasspublicstaticvoidmain(Stringargs[]){}classMyInnerClass{}}三 程序解析題（13道publicclassHoltextendsThread{privateStringpublicstaticvoidmain(Stringargv[]){Holth=newHolt();}sThreadName=}getThreadName(){return}publicvoidHoltfirst=newHolt("first");Holtsecond=newHolt("second");}publicvoidstart(){for(inti=0;i<2;i++){+i);}}}}first0second0first0first0first1second0classBackgroundimplementsRunnable{inti=0;publicintreturn1;}//End}//Endpublicclasspublicstaticvoidmain(Stringargv[]){Convc=newConv();Strings=newString("ello");}publicvoidamethod(Strings){charc='H';}} packagepublicclassTest{//dosomething…}classMyClass{}importjava.io.*;publicclassTest{//doimport {//dosomething…}publicclassTest{//dosomething…}importjava.io.*;publicclassTest{//dopublicclassXimplements{privateintx;privateinty;publicstaticvoidmain(String[]{Xthat=new(new(new}publicvoid{for(;;){x++;}+",y="+}}}程序打印xy這一對值在同一行中并不總是相同的，例如：“x2y1”程序打印xy這一對值在同一行中總是相同的，例如：“x1y1”。另外，每一個值只出現(xiàn)一次，例如：“x=1,y=1”接下來“x=2,y=2”。在一個行的開始顯示程序打印xy這一對值在同一行中總是相同的，例如：“x1y1”。另外，每一個值只出現(xiàn)一次，例如：“x=1,y=1”接下來“x=2,y=2”。在一個行的開始顯示classParentprivateStringpublic}publicclassChildextendsParentpublicChild()Parentp=new}}A3B6C7D8publicclassStringwebSite="h publicStringgetSite(){return}}編譯器會報錯誤：expectedforthestatementinlineintm,publicTest(inta){m=a;intj=0;}}AlineBlineClineDline publicvoidprintValue(inti,intj){//...}publicclassTeacherextendst=new}AlineBlineClineDlineStringBuffersb=newStrings=new下面line1產(chǎn)生錯誤line2產(chǎn)生錯誤line3產(chǎn)生錯誤line4產(chǎn)生錯誤line5產(chǎn)生錯誤line6產(chǎn)生錯誤line7產(chǎn)生錯誤intm,publicTest(inta){m=a;publicstaticvoidmain(Stringarg[])intj=0;t2=new}}linelinelinelinepublicclassQuiz2publicstaticvoidmain(String{trythrownew}catch(Exception{}finally}}}classMyExceptionextendsException}publicclassDeltareturntrue;}publicstaticvoidmain(String[]{inti=for(foo('A');foo('B')&&(i<2);{}}}Anexceptionisthrownat四 程序填空題（13道publicclassLin{publicstaticvoidmain(StringLinl=newLin();}publicamethod(){intia[]=newint[4];{

//StartFor}}}答案：for(inti=0ipublicclasspublicstaticvoidmain(Stringargv[]){Octo=newOct();}amethod(){intoi=}}publicclasspublicstaticvoidmain(Stringargs[]){Integerb=newInteger(10);Add(b);}b){intI=Value();b=new}}publicclassTest1{for(inti=-2;i<2;i++){if(i==0)continue;}}}classarray3publicstaticvoidmain(Stringargs[])inta[]={1,4,6,9,13,16,19,28,40,100,0intnumber=inttemp1,temp2,end,i,j;for(i=0;i<10;i++)System.out.print(a[i]+"");System.out.println("Thenumbertoinsert:"+number);end=a[9];if(number>end)a[10]=number;elsefor(i=0;i<10;{if(a[i]>{temp1=;for(j=i+1;j<11;{temp2=a[j];a[j]=temp1;temp1=temp2;}}}}for(i=0;i<11;i++)System.out.print(a[i]+"");}}publicclassTestdo{}while(--m>10}{intTestt=newTest();}}publicclasspublicstaticvoidmain(Stringargs[]){Strings1=”HenryLee”;Strings2=”JavaApplet”;Strings3=”Java”;Stringst; }}JavaimportpublicclassSortArraypublicstaticvoidmain(Stringargs[])String[]str={"size","abs","length","class"};for(inti=0;i<str.length;i++)}} { show(){}} { show(){}}若在應(yīng)用程序的mainAa=newA();Ab=newB();ClassA:a=1ClassA:a=1ClassB:a=3.0d=Java (j) System.out.print(“Valueistwo.”); 2+1:System.out.println(“valueis“+