大学期末考试-Java题库

1.下面程序的运行结果是（）。publicclassE3{publicstaticvoidmain(Stringargs[]){Strings=大大;chara=s.charAt(2),b=s.charAt(4);System.out.print(a);System.out.println(b);}}2.下面程序的运行结果是（）。importjava.util.*;publicclassLinkedListExample{publicstaticvoidmain(Stringargs[]){LinkedListlinkedlist=newLinkedList();linkedlist.add(newInteger(1));linkedlist.add(newInteger(2));linkedlist.add(newInteger(3));linkedlist.add(newInteger(4));linkedlist.add(newInteger(5));System.out.println(Theoriginalcontentsofthelinkedlistis:);System.out.println(linkedlist);linkedlist.add(2,hello);linkedlist.addFirst(First);linkedlist.addLast(Last);System.out.println(Afteraddingelements，thelinkedlistis:);System.out.println(linkedlist);}}答：3.下面程序的运行结果是（）。publicclassTestArray{publicstaticvoidmain(Stringargs[]){inti,j;inta[]={5,9,6,8,7};for(i=0;ia.length-1;i++){intk=i;for(j=i;ja.length;j++)if(a[j]a[k])k=j;inttemp=a[i];a[i]=a[k];a[k]=temp;}for(i=0;ia.length;i++)System.out.print(a[i]+);System.out.println();}}4.下面程序的运行结果是（）。publicclassTryCatchFinally{staticvoidProc(intsel){try{if(sel==0){System.out.println(noException);return;}elseif(sel==1){inti=0;intj=4/i;}}catch(ArithmeticExceptione){System.out.println(Catch);}catch(Exceptione){System.out.println(Willnotbeexecuted);}finally{System.out.println(finally);}}publicstaticvoidmain(Stringargs[]){Proc(0);Proc(1);}}5.下面程序的运行结果是（）。publicclasswelcomeTest{publicstaticvoidmain(String[]args){Strings,s1=;charc;s=wELCOME;for(inti=0;is.length();i++){c=s.charAt(i);if(c='a'&&c='z'){s1=s1+Character.toUpperCase(c);}else{s1=s1+Character.toLowerCase(c);}}System.out.println(s1);}}6.下面程序的运行结果是（）。publicclassarrTest{publicstaticvoidmain(Stringargs[]){inti,j;inta[]={2,1,4,8};for(i=0;ia.length-1;i++){intk=i;for(j=i;ja.length;j++)if(a[j]a[k])k=j;inttemp=a[i];a[i]=a[k];a[k]=temp;}for(i=0;ia.length;i++)System.out.print(a[i]+);System.out.println();}}7.下面程序的运行结果是（true,false）。publicclassStringTest{publicstaticvoidmain(Stringargs[]){Strings1=newString(abcde);Strings2=newString(abcde);booleanb1=s1.equals(s2);booleanb2=s1==s2;System.out.print(b1+,+b2);}}8.下面程序运行时，若输入10，则输出结果是（）。publicclasstest{publicstaticvoidmain(Stringargs[])throwsIOException{BufferedReaderbuf=newBufferedReader(newInputStreamReader(System.in));while(true){Stringstr=buf.readLine();if(str.equals(quit))break;intx=Integer.parseInt(str);System.out.println(x*x);}System.out.println(“OK”);}}9.下面程序的运行结果是（）。publicclassT{publicstaticvoidmain(Stringargs[]){Setset=newHashSet();set.add(newInteger(10));set.add(newInteger(5));set.add(newInteger(15));set.add(newInteger(5));set.add(newInteger(10));System.out.println(size=+set.size());Iteratorit=set.iterator();while(it.hasNext()){System.out.print(it.next()+);}}}10.下面程序的运行结果是（）。publicclassA{classDog{privateStringname;privateintage;publicintstep;Dog(Strings,inta){name=s;age=a;step=0;}publicvoidrun(Dogfast){fast.step++;}}publicstaticvoidmain(Stringargs[]){Aa=newA();Dogdog=a.newDog(Tom,3);dog.step=25;dog.run(dog);System.out.println(dog.step);}}11.下面程序的运行结果是（）。classA{intx=1,y=2;doubleadd(){returnx+y;}}classBextendsA{intx=10,y=20;doubleadd(){returnsuper.x+super.y;}}classTakecare{publicstaticvoidmain(String[]args){Aa=newA();Bb=newB();System.out.println(a.add=+a.add());System.out.println(b.add=+b.add());}}12.下面程序的运行结果是（）。for(inti=0;i5;i++){switch(i){default:System.out.print(default\t);case0:System.out.print(zero\t);i++;break;case1:System.out.print(one\t);case2:System.out.print(two\t);i++;}}13.下面程序的运行结果是（）。publicclassExample{Stringstr=newString(good);char[]ch={'a','b','c'};publicvoidchange(Stringstr,charch[]){str=testok;ch[0]='g';}publicstaticvoidmain(Stringargs[]){Exampleexample=newExample();example.change(example.str,example.ch);System.out.print(example.str+and);System.out.print(example.ch);}}14.下面程序的运行结果是（）。classA{publicStringShow(Dobj){return(AandD);}publicStringShow(Aobj){return(AandA);}}classBextendsA{publicStringShow(Bobj){return(BandB);}publicStringShow(Aobj){return(BandA);}}classCextendsB{publicStringShow(Cobj){return(CandC);}publicStringShow(Bobj){return(CandB);}}classDextendsB{publicStringShow(Dobj){return(DandD);}publicStringShow(Bobj){return(DandB);}}publicclassmain{publicstaticvoidmain(Stringargs[]){Aa1=newA();Aa2=newB();Bb=newB();Cc=newC();Dd=newD();System.out.println(a1.Show(b));①System.out.println(a1.Show(c));②System.out.println(a1.Show(d));③System.out.println(a2.Show(b));④System.out.println(a2.Show(c));⑤System.out.println(a2.Show(d));⑥System.out.println(b.Show(b));⑦System.out.println(b.Show(c));⑧System.out.println(b.Show(d));⑨}}15.下面程序的运行结果是（）。publicclassExampleextendsTT{publicstaticvoidmain(Stringargs[]){Examplet=newExample(Tom);}publicExample(Strings){super(s);System.out.println(Howdoyoudo?);}publicExample(){this(IamTom);}}classTT{publicTT(){System.out.println(Whatapleasure!);}publicTT(Strings){this();System.out.println(Iam+s);}}16.下面程序的运行结果是（）。publicclassExample{publicstaticvoidmain(Stringargs[]){for(inti=0;i2;i++){resume:for(intj=0;j3;j++){for(intk=0;k2;k++){System.out.println(i++j++k);if(i==1&&k==0)breakresume;}}}}}17.下面程序的运行